The thompson was only issued in 45acp... The 'Greaser" was issued in 45acp as well... But some conversions to (9mm Para) for the M2/3 were made... They consisted of barrel, bolt, main spring, and magazine... I think the idea was to drop them to resistance fighters in europe... the same way the brits did with the STEN... Don't know if any were ever used....
OG