Here is an original 1950's vintage Meyer Bros 4M baritone mouthpiece. This mouthpiece measures .088" on my gauge.
In the world of mouthpieces, the Meyer Bros (Frank and Ed) need no introduction. These two former Otto Link apprentices began producing mouthpieces under their own name in the late 1930's.
This particular piece is from the second generation of Bros pieces that were made in Northport NY and has the words "Medium Chamber" stamped on the table side of the shank.
This is certainly a rarity to see not only a 'Bros' era Meyer baritone mouthpiece but one so amazingly clean. This mouthpiece only has a few small scratches and nicks and has been in storage for decades. It came with a matching 'Bros' soprano (!) that didn't even make it to the site.
If you are looking for an incredible jazz setup for baritone, this one is fantastic as is but also has a generous tip thickness that would allow for this to be customized at a more modern tip size without sacrificing the spirit of the original.