I had a M1928 Sub-machinegun. It was a West Hurley "modern manufacture" in that it was made in the 70's or 80's. The class 3 SMG's were made the same as the original TSMGs. They made these the same time they also made their M1927 semi. As noted, the M1927's were a different design, being closed-bolt and some slight changes so you couldn't just drop in SMG parts and make a machine-gun.
At the time, aside from the SMG's, Auto-Ordnance made the semi-1927 in a carbine format with a 16+ inch barrel, a light-weight version using alloy parts, and a pistol version, which had the SMG barrel, but not stock. There was also a .22LR version, and they had listed various other calibers, like 10mm, etc. I've never seen one in the other centerfire calibers, but some people have said they saw prototypes at various times. Most people probably just want a Thompson in .45 anyway. They also made a semi version of the M1A1 TSMG.
A-O used to sell a plate that you could screw onto the bottom of the receiver of the pistol and turn it into a SBR. The plate would accept the M1928 detatchable stock. I don't know if it's still available, or even compatible with the late guns.
It was a fun gun, especially full-auto. It was very controllable. Ergonomically, it sucked frankly, but with a 50rd drum you could put out a heck of alot of lead.
The biggest problem with the closed-bolt semi is with the drum. It takes three hands to put the drum into the gun. I think Khar sells some kind of gizmo that will hold the bolt open to insert the drum. Maybe it's included. Either way, if you get a closed-bolt gun and you're going to use a drum, definately have the gizmo.
There was also a gun that resembled the Thompson that was a semi-auto that fired from an open bolt. It was a completely different design in reality, but it sorta looked like a Thompson, for obvious marketing reasons. They had to change the design to closed-bolt, though the few open bolt guns were grandfathered. Many folks get these guns confused with the guns built on the real Thompson design.