I would look into this website:
http://cderksen.home.xs4all.nl/Conn38B1958image.html. It goes into detail on the 38b and reviews by a symphony trumpet player.
According to the website, your model (according to the serial number) was made in 1958. To be honest, I do not know much about the horn other than (when I tried it) it is built very sturdy and you get a good tone out of it. My general rule when it comes to old horns is: older is better. Older models (there are exceptions, but Conn is not one of them) were usually built by hand and carefully crafted to every last inch so it can be consistent forever. Newer models used other methods as a means of experimentation, as well as to meet consumer demands. There is a less personal touch and are made with cheap material too, so they last much shorter and need more maintenance. In your case, that 38b you are inquiring is very good quality and should be well worth the money.
This is just an educated guess (generalization), therefore if I were you I would consult a horn maker or someone that has a better knowledge of it than me.
Hope this helps!
belltrumpetplayer19
