Last week I bought a Conn sousaphone which my local brass expert tells me is a 38K. However, the serial number on the instrument is 534057, which according to Music Trader, would date it as 1955 production. Was the 38K still being made in 1955? I've seen references online (e.g. here) to production ending as early as 1931. If this is not a 38K, what is it -- maybe a 14K or 32K?
Here are a few pictures of the horn, including closeups of the S/N and the engraving on the bell. One other unusual (?) feature I'll mention is that there are only 2 bell screws.



Thanks for any info you can give me.




