Vintage Glastex (B) Trade Mark Made In USA Plastic Trumpet Mouthpiece

Description

Vintage Glastex (B) Trade Mark Made In USA Plastic Trumpet Mouthpiece.
In order of appearance around the rim: Glastex, Made in U.S.A. ,“B” (is actually a “B” inside a circle), Trade Mark (the words “Trade Mark”).
Not sure what type of plastic it is, possibly Bakelite? 2 1/8” high.
I got this from an elderly trumpet player who also had an uncle who ran a musical instrument repair shop for decades in New York. This mouthpiece is from this large lot. Due to the amount of years these mouthpieces span I can’t say what era these mouthpieces are from. Look for other mouthpiece and instrument listings - I will be posting many more from this lot.