Hmmm, after further investigation, I believe you are right. The mags will be for an S not a C, BTW. I have already purchased the sleeves. I could just use the plates from my S mags, just for starters. If I like (this is just an experiment) then order some more plates. The Pro Mags are on the way. Will check them out, see what I think. Even if I like them, I still may order some OEMs.Remove the +2 for a original end.
Let us know how the Pro Mags work.
I bought some 30 years ago and never bought another one. Yes it was that bad.