Conn trombone recognition guide
Here is my attempt at a Conn trombone recognition guide. I admit that I am less adept at spotting the differences between Conn trombones. Consequently, this is only a general guide covering mostly instruments of 1945 and later.
There are three approaches to figuring out what model an instrument is. The first is through the serial number and either the model number stamped on the instrument or the model name engraved on this instrument. The second approach is to look at the features of the instrument. I will first deal with recognizing a model through names and numbers. If you don't know or can't tell the name and numbers on an instrument, scroll down to the section titled "Recognizing an instrument by its features". Thirdly, I give a list of which trombones have what bell size (have your tape measure ready! For the metric readers: an inch is 2,54 centimeters, and as usual European commas are American periods for decimal calculations).
Recognizing an instrument through names and numbers
The very first thing you need to do is to check and look up the serial number. On Conn trombones I believe(!) that the serial number is stamped near where the slide and bell sections are joined. Check the number stamped there against the Conn brass serial number list. This should tell you what year the instrument was built. Note that serial numbers on Pan American models don't match Conn serial numbers.
The next thing to do is to check for model names or numbers. For a period from the mid 1920's through to the mid-1950's Conn stamped the model number right above or below the serial number, where the bell and slide sections come together. If you see a model number there (such as "1 2 H"), you are home free. Else check if there is a name engraved on either the side of the mouthpiece receiver/leadpipe or the bell. Check that name against the list below, which also gives some distinguishing features.
If the name engraved on the leadpipe is "Director" it is either a 14H or a 18H. If the instrument has a Coprion bell it is an 18H. If it has a brass bell, it is a 14H. Both the 14H and 18H Directors have a 7½" bell.
It's probably a 77H. The 77H was produced from 1957 into the 1970's. In 1954 and 1955 Conn produced a 20H Connquest. These are quite rare. If your Connquest has a serial number in the 400,000 or 500,000 range it should be a 20H. If the serial number is 600,000 or above, it is almost certainly a 77H. The 20H has a 7" bell, the 77H has a 7½" bell.
As far as I can tell, the Victor models (4H, 6H and 10H) didn't have "Victor" engraved on the mouthpiece receiver or the bell. However, the 10H has a distinctive 8" Coprion bell, and nickel trim (as opposed to the 18H which doesn't have the nickel trim). Serial numbers of the 10H should range from 5xx,xxx or 6xx,xxx to 9xx,xxx. The 6H is identical to the 10H except it doesn't have a Coprion bell. It was produced for a longer time: 1947-1979 (serials 36x,xxx - GL9xx,xxx). The 4H was made almost continuously from 1919 to 1958, serial numbers not higher than 6xx,xxx or 7xx,xxx.
A Connstellation trombone can be either a 28H, 38H or 48H. If your Connstellation is entirely nickel plated with lacquered brass slide and tuning slide, it is a 48H. The 48H has "Connstellation" engraved on the side of the bell. I am not sure if that is also the case for the 28H and 38H. As far as I can tell the 28H and 38H are very similar. The one picture I have seen of a 28H shows the first brace on the slide section not to have curved ends for more comfortable holding, while the 38H does have that feature. However, it might be a replacement brace. The 28H should have a serial number in the range 38x,xxx-39x,xxx. The 38H should have a serial number between 42x,xxx through 5xx,xxx. The 48H has serial numbers from 6xx,xxx and higher. The 28H and 38H both have 7½" bells, the 48H has an 8" bell.
This is a 1955, possibly 1954 12H Coprion. A rare instrument indeed, because in 1955 Conn modified the 12H Coprion by increasing their weight and adding nickel trim. The modified 12H Coprion was dropped in 1955 and replaced by the 10H Victor. If you own one of these 12H's with "Coprion" engraved on the leadpipe: it is rare! And please drop me a line.
Recognizing an instrument by its features
In this section I will list several features, starting with the more distinct characteristics. There is a certain amount of overlap between the features, so please read through the entire section.
If it has a Coprion bell, it is either a 10H, 12H or a 18H. The 10H has an 8" bell and has nickel trim. The 12H has a 7" bell, and I think (!) it has nickel trim. Serial numbers on the 10H should be 5xx,xxx or 6xx,xxx and higher. The 12H usually has serial numbers of 3xx,xxx through 4xx,xxx, with the exception of the 1955 12H which has Coprion engraved on the mouthpiece receiver. The 18H has nickel trim on the slide only, not on the bell. It has a 7" bell.
Red brass bell or Rose brass bell
The terms "red brass" and "rose brass" refer to the same thing: brass with higher copper content, but not pure like Coprion. An instrument like this could be a 8H, 88H, 60H or 62H. Of these instruments, only the 8H doesn't have an F attachment. The 8H and 88H have 8½" bells. The 60H and 62H models are bass trombones, both have a 9½" bell. The 62H is a dual rotor trombone, with F and D attachments.
Nickel plated bell
If the instrument is entirely nickel plated with brass slides, it is a 48H. The bell is 8", and serial numbers run from 6xx,xxx to at least GL9xx,xxx.
Single rotor/F attachment
A trombone that has only one (!) rotor, the "F attachment", can be a 88H, 60H, 71H, 72H, 70H early, 70H late or 50H The 88H is a tenor trombone with a 8½" red brass bell. The others are bass trombones. The 60H has a 9½"red brass bell. The 70H has a distinctive hand slide tuning mechanism with adjustable screw. The 50H has a brass bell with a 8½" bell. The 71H and 72H are very similar. Both have 9½" brass bells. The 72H should have a serial number in the range 5xx,xxx-Kxx,xxx. The 71H should be Lxx,xxx and up. I recommend looking at the pattern of the F-attachment tubing when in doubt.
No bell rim wire
Connqueror, 44H. This is the "vocabell" model.
Recognizing an instrument by bell size