I was looking around the ATF site and didnt find that, but yes it is surprisingly detailed. Lot of interesting reading/debate on the subject around the internet also. Never really looked into it until now.
So the Stens I was looking at were nowhere near cut like those illustrations. I wonder if they were ever 'legal' demils. They were each in an old importer's box..
The Bren kit I used looks 'legal' with three diagonal torch cuts and there were some gaps, although not as enthusiastically melted like the latest parts kits.
I agree it would hurt to take a torch to that MK1 but I wouldnt want it in my house if its considered a MG. Most likely a semi auto builder wont even touch it as-is.