The Quickie Bit About Student, Second-Line and Stencil Horns
I wrote an article on this for SOTW some time ago, but I'll post some highlights.
1. A "stencil" is a saxophone built by a "major" instrument manufacturer for another manufacturer, dealer or storefront. This horn is produced without engraving. The dealer (etc.) then takes a stencil and uses it to engrave something on the bell.
* European and Japanese stencils are generally EXACTLY like the pro/intermediate horns they are stenciled from, except for the engraving: for instance, a King Marigaux is exactly the same as a SML Gold Medal around the same serial number. A Vito stamped "Made in Japan" is the same as a Yamaha 23. (In general terms, of course. Some King Marigaux horns have altissimo F# keys and the Yamaha Vitos have different lacquer.)
* American-made stencils usually are missing some features from the model they are stenciled from: for instance, A Selmer NY Conn stencil has the same bore and keywork as a Conn New Wonder made around the same time (usually), but does not have the New Wonder's rolled toneholes and has a different series of serial numbers. Additionally, many American-made stencils are lower quality than the horns they were stenciled from: for instance, any Conn stencil engraved "Cavalier" is generally junk and you should run away, screaming. The Selmer NY horns are generally extremely good.
2. A "second-line" horn is generally a US-made horn produced at a different factory, usually made differently than the professional model. For instance, a Conn Pan American generally has a completely different patent stamped on the horn than a Conn New Wonder and it was made with different tooling. The Pan American isn't a "New Wonder, Jr.", it's a completely different horn and has its own series of serial numbers.
3. "Student models" are also completely different. They are generally made with a different bore, cheaper tooling, cheaper materials, etc. than professional horns. That's not to say that there aren't excellent student horns out there (Yamaha 23), but that they're just not in the same class as professional horns from the same company. In other words, DON'T compare a Yamaha 23 to a Conn New Wonder (which might disappoint New Wonder owners), compare a Yamaha 23 to a Yamaha 62.
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Some Interesting Exceptions/Notes
SML, being SML, also did something that I've not seen repeated with any other manufacturer: they'd come out with a new model professional horn -- say, the Gold Medal -- and would continue to sell their old professional model (the "Rev. D", using my Gold Medal example) under a different name, "Standard", probably until they ran out of fully assembled horns that used the old tooling.
Holton also did something unusual: in the late 1930's and 1940's, they produced some horns for Gretsch. These horns are reportedly considerably better than any other Holton models and are favorably compared to Conn Artist/Standard ("Naked Lady") horns, rather than other Holtons.
In the 1920's, Holton (and later, Martin) also produced a horn designed for Lyon and Healy: the Perfect Curved Soprano, generally sold under the Lyon and Healy Name of "American Professional". I can't say if Holton "designed" the instrument or if L&H did, but it's a) rare, b) expensive, and c) unplayable. (The Perfect Curved soprano is possibly the only saxophone that really is junk that's valuable.)
Martin later went on to design the Olds Super horns, which were terribly unlike any other Martin-made instruments and are extremely good players, from what I'm told. Allegedly, these were all military-issue instruments.