TubeNet

I bought my son a 1920 CG Conn tuba and am looking for more information.
# on the valve is 171216
It has 3 top valves and a 22" bell. I have no idea about the bore...don't even know what that is. I believe it is a Bb, but not sure.
Woudl post a photo but haven't figrued out how yet .
Thanks for any assist in information.

If you don't know about it already, Christin Derksen's Conn Loyalist site at http://www.xs4all.nl/~cderksen/ is a good source for Conn related questions.