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National Style O Resonator Value Guide (1930 to 1941)
A National Style O is a single-cone resonator guitar built from 1930 to 1941, with a nickel-plated metal body and sandblasted Hawaiian scenes. The painted Duolian and Triolian are its plainer siblings. Value rides on an original cone and coverplate, even plating and a crisp etching. Call or text (440) 219-3607 or text us photos.
What a Style O looks like
The Style O is the plated one. The body is polished metal with nickel plating, palm trees etched into the front, and a Hawaiian scene sandblasted into the back. The first several hundred were made of steel, which plated poorly, so National switched to brass early on. Almost everything you will see is brass.
It has one cone, the "biscuit" resonator, under a coverplate. Do not confuse it with National's tricone guitars, which have three cones. Collectors sort Style Os into numbered variations, because the body, the etching and the neck changed over the 11 years National built it.
One warning before we go further. National Reso-Phonic still builds a modern Style O that copies the original, and dealers list it in the same search results as the prewar guitars. If the plating looks perfect, rule out the reissue before anything else.
Style O vs Duolian vs Triolian
If you inherited a "National" and are not sure which one it is, start with the finish. Plated and etched is a Style O. Painted is a Duolian or a Triolian. All three use a single cone.
Model | Body and finish | Cone | Quick tell |
|---|---|---|---|
Style O | Nickel-plated brass (steel on the first several hundred), etched Hawaiian scenes | Single cone | Shiny metal with palm trees on the front |
Duolian | Steel body, painted | Single cone | Frosted "duco" paint with a crystal-like texture, later a painted wood-grain look |
Triolian | Painted, multi-hued finish, steel body on most (the earliest were wood) | Single cone, despite the name | Colorful painted finish, often with decals or a sunburst |
The name "Triolian" trips people up. It sounds like three cones, but the Triolian "still had only a single resonator cone, despite its name," as the guitar.com review of a 1932 example puts it. The tricones are a separate line.
How to date a Style O
National built the Style O from 1930 to 1941, and the changes give you a rough window before you look at any serial number.
Body size: early Style Os have a 12-fret neck, meaning twelve frets clear of the body. In late 1934 National moved to a smaller body with 14 frets clear. A 14-fret Style O is mid-1930s or later.
F-holes: the f-holes in the upper body were straight-cut at first. From 1933 the edges were rolled for a smoother look.
Material: a steel Style O is very early, from the first several hundred guitars.
Etching: the sandblasted scene changed over the years, which is part of why collectors talk in variations.
Treat the serial number as one clue, not the answer. Check it against the body size, the f-holes and the etching. If they disagree, tell us, because a mismatch is worth understanding before anyone talks about a price.
The same model as the Brothers in Arms cover
Many people first hear about this guitar from a record sleeve. The Style O is the same model as the one on the cover of Dire Straits' Brothers in Arms, a guitar dated to about 1937. That guitar and the one we bought are two different instruments, and a famous cover does not set the price of yours.
A 1930s Style O Edgewater bought in August 2026
In August 2026 we bought a National Style O from the family of the original owner, in the Midwest. It is a 1930s guitar, and it was in great condition. It still had its original pickguard.
The pickguard showed some off-gassing. Old celluloid is unstable and breaks down with age, and the usual results are shrinking, curling and cracking. A guard that has begun to break down is a normal sign of age on a guitar this old. Sellers sometimes replace a failing guard with a modern copy. That is understandable, but we would rather see the original, even if it looks rough, and we always ask. Keep the guard with the guitar, and do not try to seal or "fix" it yourself.
What moves the value of a Style O
A Style O is mostly worth what it still has of itself. These are the things we check first.
Factor | Why it matters |
|---|---|
Original cone, biscuit and coverplate | The resonator parts make the sound. A guitar with the parts it left the factory with is worth more than one with swaps. |
Plating | Even plating with normal age wear is what we hope to see. Heavy wear, polishing through the nickel, or a re-plate all lower the number. |
Etching depth and condition | The sandblasted scene should be crisp and consistent. Over-polishing softens it, and that cannot be undone. |
Round neck vs square neck | The great majority are round neck. Square-neck Style Os turn up now and then and appeal to a different buyer. Tell us which you have. |
Year signals | 12-fret vs 14-fret, f-hole style and the etching help place the year, and an early steel-bodied example is a different guitar from the usual brass. |
Repairs, cracks and dents | Body dents, neck repairs and cracked wood all count against it, even when professionally done. |
Case | The original case helps confirm the guitar has not been reworked. |
Pickguard and small parts | Original celluloid, even aged, beats a replacement. |
What a National Style O is worth
We are not going to hand you a number we cannot back up. Prices for prewar Style Os vary a lot by year, 12-fret or 14-fret, plating condition and originality. The range is wide, so any single figure for "a Style O" would mislead you.
What we can tell you is how we think about it. A clean, original example with its cone, biscuit and coverplate, good plating and a crisp etching sits at the top of the range. A re-plated, polished, dented or part-swapped guitar sits well below it. Edgewater's cash offer usually lands about 20% under what a comparable guitar sells for on the open market, and less for refinished or modified examples.
The accurate number for your guitar comes from photos, so start a free estimate, or check what's my guitar worth for a first read.
How to sell your Style O
Send photos of the front, the back with the etching, the coverplate and biscuit, the f-holes, the neck and headstock, the serial number if you can find it, and the case. Mention any dents, repairs or parts you know were replaced. Do not clean or polish the metal first.
If the guitar came from a family member's estate, our estate page explains how we work with executors and heirs, and the executor guide on inherited guitar collections covers what to do before you sell. For a single instrument, our acoustic guitar page covers the process. We buy nationwide from our base in Valley City, Ohio, near Cleveland.
Diane D. wrote this about an earlier appraisal: "I had a great experience talking to Gavin regarding the value of several of our guitars. He was very knowledgeable, provided lots of good information, honest, listened and responded to my questions promptly. It was a pleasure talking with him and I would not hesitate to recommend Gavin to anyone interested in getting an estimate or selling their guitars."
Frequently asked questions
What is the difference between a Style O, a Duolian and a Triolian?
The Style O is nickel-plated brass with etched Hawaiian scenes. The Duolian and the Triolian are painted steel guitars, the Duolian with a frosted, crystal-textured paint and the Triolian with a multi-hued painted finish. All three have a single cone.
How do I date a National Style O?
Use the body and the details together. A 12-fret neck points to 1930 through about 1934, and a smaller 14-fret body came in late 1934. Straight-cut f-holes are earlier, and rolled f-hole edges began in 1933. The serial number is a starting point, not a final answer.
Is a replaced cone a problem?
For value, yes. Originality is a large part of what a collector pays for, so a replaced cone, biscuit or coverplate lowers the number. It does not make the guitar worthless, and it still plays. Tell us what was replaced when you send photos, and do not hide it.
What is a Style O worth?
It depends on year, plating, etching, originality and the case, and a prewar Style O can range widely. We do not quote a flat number. Send photos for a free appraisal. Our cash offer usually lands about 20% under market, and less on refinished or modified guitars.
Should I polish or re-plate my Style O before selling it?
No. Polishing can wear into the nickel and soften the etching, and a re-plate hurts originality. Leave it as it is, keep the case, and send photos.
Edgewater Guitars. Last updated: October 2026.
