It's a 90 opening and my vernier shows 2.2mm at the tip center and 1.8mm at the tip sides. Table rails and tip very good. Needs a ligature of 22.5mm approximately. I might be able to find one if you ask. I got this mouthpiece when i was trading saxophones a few years ago.
Not sure what it's worth. The item "Berg Larsen Precision Alto mouthpiece Very Vintage" is in sale since Sunday, October 08, 2017. This item is in the category "Musical Instruments\Wind & Woodwind\Band & Orchestral\Saxophones". The seller is "rollonin" and is located in Stevenage. This item can be shipped worldwide.