They occasionally come up for sale on GunBroker-Auction.........and may be able to be found with some of the surplus parts dealers such as Allegany-Arsenal over in PA-?
Use of Blanks will depend on who's Blanks for the restriction size as they are not all the same. (IE: Just because it is a "Blank" does not mean it will be the correct loading for your gun's BFA - Blank-Firing-Attachment)......there are low powered Blanks out there...along with Grenade-Launcher-Blanks.......and even different loadings for the movie and reenactor businesses.
Bob,
Kahr-Arms may have bought the "Thompson" Trademark-Name........but as these parts, assemblies, and 80% receivers have been sold by numerous Companies and individuals over many years.....look into what is "Public-Domain".
Regards, RichardS
If these will not be manufactured in the future......will just the 80% M1 or 80% M1A1 engraved steel receivers be manufacture by Phila. Ordnance soon (?).
Next....once we get the how-to sorted out.....you may need to place an ad over on the "Weapons-Guild"........."Want Someone To Make a Few Magazines For Me.". There are several persons over on that Boad that could make these for you.....or may have already made them (?).
If I didn't know better, the magazines appears to have been made with a standard 30-rd. Thompson magazine.......with the front cut out and some type of standard (cheap) 9mm SMG magazine used for the modification (.....such as a Sten-Gun-Magazine.....or Vigneron (?)). Placed in to feed to the rear, then welded in place (?). Take a photo with the magazine baseplate removed (if possible) to see inside.