The Sig Service plan is a good deal. If you intend to skip that then just clean it, swap out the recoil spring and shoot the poop out of it. And correct, dump that Promag and never buy one again. CDNN has good pricing on 7 and 8 rd mags from MecGar and Sig and shipping is cheap. I pick mine up from them. Enjoy that thing, it's a good pistol.
220ST, P228, Two P6's