It didn't take long for me to regret it after I sold my Winchester 1300 Stainless Marine so I decided to look for another one. What I found was a great deal on a new-in-box 12 gage Winchester 1200 Stainless Police with the optional rifle sights from around the early to mid Eighties.
There's not a lot of information to be found about this particular shotgun but most sources agree that Winchester didn't go to 3" receivers until the Model 1300 came out. So I almost passed this one up but fortunately decided to take a look at it anyway. I was quite surprised to find that it actually featured a 3" receiver especially so because the seller wasn't even aware of it. (A 3" receiver takes Magnum shells versus the regular 2 3/4" shells.)
It seems like there were a service and a civilian version of the Stainless Police available. Early models supposedly featured actual stainless steel barrels while later models were chrome plated with a satin finish. Mine says Winchester Proof Stainless Steel on the barrel which seems to indicate that it's stainless steel but then Winchester also liked to call plated shotguns stainless so I think it's probably nickel plated with a satin chrome finish. I'm also pretty sure that the receiver is made from aluminum, some sources mention service versions with steel receivers.
Compared to the Model 1300 Stainless Marine there are only minor differences. The 1200 Stainless Police is noticeably heavier probably due to the wood stock and features no plastic parts in the trigger group. It actually feels like a higher quality firearm compared to the later Model 1300. The ejector isn't screwed to the receiver, the firing pin looks a bit different and the slide arm bridge is attached to the bolt with a screw that needs to be removed before you can slide the bolt out of the receiver.
All in all I consider the Winchester 1200 Stainless Police a step up from the 1300 Stainless Marine even though the 1300 series should have been an improvement over the 1200 series. As so often with guns improvement in this case obviously just meant cheaper to manufacture.