I hope someone can help me out on this.

My band has two Lafluer(not sure how to spell, sorry) Euphoniums... or i`m not sure if they are baritones.... coz it`s like in-between a baritone and euphonium... and the mouthpiece shank is very large.. larger than the other Yamaha Euphonium mouthpieces and the Boosey & Hawkes Regent Baritone. I need to replace one of the missing mouthpieces and I`m having trouble because I can`t locate any mouthpiece with such a large shank. Why are the Lafluer Euphoniums shank so big? Besides, are they Euphoniums or Baritones? One of the nearby bands has one Lafluer identical to ours but they labelled it as a Baritone. Can anyone help?? thanks! =)

why dont you look at some teombone mouth piaces? they somtimes can work on baritone or euphoniums.
When I was in high school i lost my mouth piace to my baritone so I stole a T-bones extra mouth piace. And it worked just fine.