non-buyer's remorse

[eupher61]

much less the suspicious thread about a seller not contacting a buyer...

[swillafew]

I can't make the specific comparison, but the 67C4 worked fabulously for me for 15 years as an F tuba mouthpiece on a small Rudy Meinl. I hoped it would play in tune on the GR51 tuba I bought, and it was not well in tune on that horn. When I acquired a PT-10, the 67C4 worked well, but I went with a Helleberg instead, for a weightier sound. Now it's on the shelf.

[Donn]

Alas, no one knows.

It would be a contribution that we would cherish forever, if you would just buy all those mouthpieces, and write up accurate physical comparisons vs. their apparent counterparts. Personally I'm not so interested in the 68B or anything that bears the least resemblance to a C4, but ... is the 66 like a Schilke 66, or what? What about the 66B, is it closer to a Schilke 62 or a Laskey 28F? Rim shape? Measurements from your well equipped laboratory would reveal the inner secrets of these mouthpieces in a way that eclipses anything the casual Tubenet commenter could do, maybe you could even measure exotic parameters like throat length.