D- Definitely K frame, they fit my 1952 Combat Masterpiece very well. Like gunhacker says, I’ve not seen a set marked like these . I agree, “KT” is K frame . They are also marked RH and LH for the respective stock panels. That’s what made me wonder about aftermarket. The black stock circles look like S&W, and they sure have the appearance of factory walnut stocks. I bought them off eBay, so I have no history on them. Don’t remember the seller description either, although I’ve learned to add a 5# bag of salt to the description! Thanks,guys! Hank