You're refering to Links.
This is from Theo Wanne's site.
EARLY BABBITT "SUPER TONE MASTER" (1975 to 1979):
These mouthpieces were the first produces at the Babbitt factory after Otto Link's move to Elkhart, Indiana. They tended to have very good projection, and were quite bright due to a high step-baffle. The window was narrower at the tip, adding a bit more focused sound than the earlier Florida models. They had a larger font number stamped on the side of the body, had a larger bore diameter, and were silver plated under the gold. The metal soprano pieces moved permanently to a very small chamber, providing a brighter sound. They were faced with the new grinding wheel, leaving very distinctive denim like patterns on the table of the mouthpiece.
EARLY BABBITT "TONE EDGE": (1974 to 79):
These mouthpieces are the first to have the signature of Otto Link written straight across the back of the mouthpieces. They read USA on the shank and had a larger inner bore diameter. They had about the same amount of baffle material in them as the Florida models, but with a slightly narrower window. The hard rubber altos gained some material in the baffle area and floor, increasing their projection. The sopranos moved to a smaller chamber (just a little larger than the vintage Selmer Soloist pieces), giving them a very nice sound similar to the vintage Selmers.