This was the first year Selmer offered the famous offset right hand keys. Hence the Creation of the First comfortable SBA. Thick, warm, gutsy tone throughout with a expressive Trane like sound, Free Blowing.
Also http://www.saxpics.com/selmer/sba.htm

This Selmer Original # 35,03X is from my personal collection
and has been Hand Selected from The Best Instruments Imaginable

Overhauled to Perfection with Lucien Deluxe Pads, $18.5K