Trebor,
I might be wrong, but I think the Thompson and the Tommy gun are one and the same. The difference is that the US Army verison normally had a 20 round clip. A drum magazine that held a lot more (90 or so) was also available and this was the gun used in all those 1930s gangster films.
While you're at it, why not see if anyone can model a violin case?
Cheers,
Ade