Conn Model Number?

[Walter Webb]

Hey, Conn identifiers! What model is this?
I have been told that this is a 35j or 37j.
It's a US Navy horn. Ser #341,xxx ('41-'42), 20 inch fixed bell, .750 bore, and traditional long pistons.

I got it from Idaho, on Craiglist, and had the owner put it on the Greyhound. Currently getting the dead mice and hairballs chem/vibration tanked out, and the rotted spit valve pads replaced. Need one Conn Sousaphone bit for a better angle. Never played a big top valved tuba before. Feels odd so far.
Thanks...