[Gaffer]

Hmmm...looks like an early one. Reduced diameter barrel up toward chamber without cylindrical ridge cuts (maybe what looks like lengthwise fluted barrel)...also looks like an early Cutts compensator, too.

[The KG9 Kid]

1928A1, probably a Navy 'overstamp' gun. Auto-Ord had a salesman going around all over the Midwest furnishing samples of US Navy contract Thompsons to little podunk police departments that thought they needed more firepower against 'auto bandits' of the early 1930s.

It's not transferable since it is on a departmental 'Form 10'. It can only be transferred to a museum or cut up to make a parts kit minus the demil'ed receiver.

[TalonDJ]

I think it has the cuts... the picture is just low quality.