Date: 1963. Instrument found on e-bay, Owner unknown
I am calling this instrument the 37A/38A, because it is somewhat difficult to tell the difference, and the model numbers changed over the years.
The 37A was the brass bell, triggerless version made between 1961 and sometime between 1963 and 1965. During that same period the 38A was the Coprion bell version, with trigger. However, sometime between 1963 and 1965 the 38A was dropped and the 37A was renamed 38A, brass bell with trigger. At least that is the way it looks now. Truly triggerless (from factory) 37A models are rare.
Notice the trigger on the first valve. This is the short version of the, perhaps better known, "long model" (trumpet-like) 28A Connstellation cornet. Also notice the fact that this instrument does have a third slide stop screw. As far as I can tell, Conn started adding those to Connstellation and Victor models of trumpets and cornets in 1961 or so. This is based upon a picture of a 37A/38A like this one with a 1961 serial number which does have the third slide stop screw.
The pictured 37A/38A is a truly exquisite looking instrument. The 37A/38A Connstellation short model cornet has a #2½ bore (0.485"), and a 4 13/16" "Electro-D" bell. The bell on the 28A and 38B models is 5 1/8", so the bell on the 37A/38A is slightly smaller. It is nickel plated with brass trim and has top spring valves (in 1961 and 1962 these would have been Tri-C valves). The 37A/38A weighs in at 2 lbs 13 oz., so it is definitely a heavy weight instrument. Production of the 37A/38A started in 1961, although a 1959 model in the Elkhart County Historical museum suggests Conn made at least one prototype or pre-production model in 1959. A 1966 catalog lists only the 38A however, and makes no mention of a Coprion bell. I suspect that in 1963 (but no later than 1965) the Coprion bell "38A" was discontinued and the 37A was renamed the 38A. This later version 38A was in production through at least 1971. However, I know someone who looked down the bell of a 1968 38A Connstellation with a bore scope and saw copper, suggesting a Coprion bell. Production of professional model instruments moved out of Elkhart, Indiana to Abiline, Texas in 1971. Instruments produced in Elkhart should have the "Elkhart" engraved on the bell where it says "C.G.Conn LTD., Connstellation, Elkart U.S.A.". Instruments produced in Abiline have the same engraving but without the word "Elkhart".
What Conn said in 1963:
The new, classic, short model cornets which have become so popular with professionals and serious students. The 38A has the dark "true" cornet tone. This model has trigger and electro D bell. The 37A has a slightly lighter tone ... with brass bell and no trigger.
What Conn said in 1966:
The world's highest degree of brasswind refinement in a short model cornet. Favorite of professionals and serious students for its free blowing and large bore feel. Electro-D mouthpipe and bell. Third valve slide throw ring. First valve trigger. Micro-finish mouthpipe. Length 17 1/8". Bell 4 13/16".