This is a Conn 12B Bb trumpet. The 12B is very similar to the more common 22B model but with a Coprion bell. The 12B was introduced in 1938 and made until 1955 so this is a post-war horn made in the middle of the production run. The 12B was the first model to feature the Coprion bell. The Coprion bell improves projection and darkens the sound somewhat. The serial number dates this horn to early 1938 so this would have been among the first made and perhaps this is why there is not a 12B stamped on the leadpipe receiver as is typical of Conn trumpets of this era.
What Conn said in 1939:
"Built in small bore, but the seamless bell of Coprion gives it the power you would expect only from larger bore. Ease of playing, beauty of tone, accuracy of scale and amazing flexibility. Impossible to overblow or crack a note. Patented Clickless Crysteel valves. Bb and A. Brass, heavily clear lacquered."
This particular 12B is straight and shows no signs of damage, which is exceptional for a trumpet that is 85 years old. It has all original parts, including the main tuning slide stop rod. It does have a fair amount of the original lacquer is missing and there is some pitting on the outside of the leadpipe, but the inside of the pipe is smooth. Valve compression and action is excellent. All slides move smoothly.
Does not come with a case.