MA548 and MA550 magazines

Anybody has a lead on any of these 2 ? Been scouring internet regularly every week and my local LGS in the area. So far no luck. Got lucky about a month ago and snagged 3 from my LGS, but thats about it. I know about ProMags, dont like em at all, have 2, unless you guys have some insights on how to make em actually functional. So far im using ProMags to train clearing malfunctions only lol.

I'm getting desperate here a bit, would like to complete a second set of 4 for USPSA matches.