Found the papers - bought it new on 2/20/83 - paid $325.
It is stamped on barrel:
"Winchester Model 1200 Stainless 12 GA, 2 3/4 & 3" ", also
"Winchester Proof Stainless Steel".
It has 18" barrel, tube holds 6 rounds of 2 3/4".
Hang tag specs say "Model 1200 Stainless, Cyl. Bore", ETC...