I'm pretty sure mine are Ks; got them with high hats of the same nature with a beat old set of Ludwigs that came from the sixties, my firs set. The drums were not worth keeping; I replaced them at first with a Simmons kit because I was playing in blues-rock bands at the time and they were JUST the ticket, then a Sonor Performer set which I still have. I kept the cymbals though; I have them in storage and can't look at them at the moment. I've got two 22" rides, one drilled for rivets, one not. They sound like Tony Williams' cymbals did in 1964. I also have a modern flat top ride bought in about 1988, a 20". That would be an "A" then.
Yeah, those would be hard to find these days I guess. Thanks for the explanation. Good luck!