Gun shop, want ads, gun shows, e-gunparts.com
I suggest that you procure a copy of the Gun Digest Assembly/Disassembly book for law enforcement weapons. The Thompson is included. Find it on Amazon.
Google.
There is a few place you can find a diagram if a strut assembly. You can find a strut assembly diagram online or at an auto part store.
Try e-gunparts.com
Take it to a gunsmith
flywheel settings
At a good gunsmith's shop. Maybe Numrich's Gun Parts (search gunpartscorp) For the complete trigger guard assembly, including trigger, safety, springs, pins etc., you can get it from Numrich, Midway USA, Brownells or direct from Marlin. If it's just the trigger or other individual trigger guard parts you need, you'll have to get those from Numrich for a different model Marlin.
You can find a Ford F550 front end assembly diagram in the owner's manual. You may also be able to find it at auto part stores.
i think now the only way to find parts is to buy a used gun from someone to fix your own.
Auto Zone? Hemmings Motor News?
in a haynes auto repair manual
No, the marker will be able to shoot rapidly without an aftermarket trigger, although if you find the trigger pull stiffer than you wanted, you can exchange the spring for the trigger with a pen spring. A light trigger pull will allow you to "walk" the trigger, which basically means you pull the trigger with two fingers (one at a time), to reach full auto- like rates of fire.