TubaForum.net

I am borrowing a friend's Conn 84I (4 top-action pistons, upright tall bell) euphonium.

Was there an in-between size for mouthpieces on these?

Small shank goes in quite far, but large shank doesn't fit.

Are these designed for something a bit larger than small shank?

This one is satin silver and marked USN on the bell. A gorgeous horn, and it plays VERY well, although just barely up to A=440.

Maybe I can convince him to sell it to me...

Euphonium mouthpieces now come in three different shank sizes. Small (same as tenor trombone), medium or Euro shank (older Bessons and Willsons) and large (same as bass trombone). However, I have heard that some of the old American made horns had a unique receiver. Kind of medium-ish, but Euro shanks don’t quite fit either. I think I remember hearing that Olds, Reynolds, and Conn used this size back in the earlier part of the 20th century. Maybe a Euro shank would be close enough, or be trimmed to fit?

Could this be a Conn "Remington shank" horn?

old Besson-B&H/English/intermediate/Willson 2900 shank size

This is probably that:

https://www.ebay.com/itm/304688478574

' pretty sure I see places where it could easily be shortened.