It's a Lyman Super-Targetspot I do believe. The book I'm looking at has 6 listed from 10x to 30x. Parallax-adjustable from 50' on out. List price was $125 or $134 with a case in 1967. (From the Shooter's Bible.)
I see they're $500+ now in 85% condition.
www.alexweb.net/unertl/lyman_stp.htm
John
Edited to add: The same book shows a Winchester 52-D with a list price of $154.95.