I don't know if anyone here is interested, but I was at the Ollie's Bargain Barn in Myrtle Beach S.C. and found in their surprisingly extensive Gun Books Section a copy [they had plenty]of "WINCHESTER SHOTGUNS" by Dennis Adler the coffee table book for $9.95. It has a section on Model 21's and Parker Reproductions that has some great photos of most of the variations of these 2 models. If you have an Ollie's nearby it might be worth a look.

H