Bach no-letter shank difference?

[Burgerbob]

Howdy y'all,

I'm certifiable and I have a small collection of the Bach small shank no-letter mouthpieces.

New York 7
Mt. Vernon 7
New York 6
small letter 5
big letter 5
Corp 3
Corp 3

The New York and Mt Vernon pieces have a seemingly different taper/shank than the more modern pieces. For instance, my small shank repair collar fits too far on my Mt. Vernon 7. All of these pieces have plating loss at the end of the shank (not suprising for a 70+ year old mouthpiece, of course), but I think it's at least partly due to them being forced into horns that they don't quite fit in. All of them wobble significantly in my 3B receiver, seemingly bottoming out against the leadpipe. In my 36, the two New York pieces wobble and the Mt. Vernon goes in much too far. The other, more modern ones all fit fine.

My Mt. Vernon 6.5AL has a completely normal shank, which makes me think they purposefully had a different one on the no-letter pieces, or I just got lucky... Anyone have some info?

[Doug Elliott]

At the time NY and MtV pieces were made, receivers were a lot less standardized than in later years.

[Burgerbob]

At the time NY and MtV pieces were made, receivers were a lot less standardized than in later years.

That was my assumption. I was just wondering if Bach were making them specifically for horns, or if they were just inconsistent (dumb question to ask about Bach, of course).