Looking for MGC 30rd mag for Thompson

Looking to buy a MGC Thompson 30rd mag

As far as I know, there were never really any MGC Thompson 30 round mags, just modified Hudson mags.

FWIW, the Hudson 30 round Thompson mag had the mag catch hole elongated to line up with the MGC mag catch. However, this still didn't address that the Hudson mag is way too tight of a fit in the MGC receiver. You can lube and force it, but it doesn't feel very good at all. And on top of that the Hudson mags generally seemed to have been made with weaker metal, resulting in the mag lips deforming with much over a 15 round load in my experience.

They still look great though and I have one that the spine of the mag has been slightly modified to fit the MGC receiver better.

Thanks this is news to me, have seen 30rd mags on MGC Thompsons but never was informed assuming they were MGC. I prefer the look. Picked up an orig WW2 30rd mag but guessing the mag spine does not fit MGC and really unsure as to reasons why the orig mag isn't able to slide into MGC being either being too wide a spine on the mag or spine depth. Unsure a dremel with guess work will aid a good outcome. Will take a close look.