I have twelve USGI 30 round mags in varying condition. 7 of them appear to have been refinished in black and are in pretty decent shape (90%+, I think) The other 5 probably vary between 20% and 50% remaining finish.
Also, 1 pre-ban C mag in excellent condition. It's been used a couple times and that's all. Unfortunately there's no pouch, loader, graphite or box. Just the mag.
I'd prefer to sell as a lot but I'll take trade offers too. Pictures available on request, because my image hosting service quit hosting images.