There are two different listings I'm posting together. Both look good and should go for very decent prices.
Schilke 51D in MEDIUM Shank, silver. Includes a vinyl case. in Starting bid $15.80 and buy-it-now is $75:
https://www.ebay.com/itm/17438418494...m=174384184946
Denis Wick SM4, large shank, silver. Starting bid $45.
SOLD FOR $45
https://www.ebay.com/itm/Denis-Wick-SM4-Steven-Mead-Euphonium-Mouthpiece-Large-Shank/114308234962