This thing?
https://www.milsurps.com/images/impo...tuff0031-1.jpg
Price seems kinda high. But I wasn't really paying attention when I got this one. Stock is welded closed so that it is really a big clunky pistol. Closed bolt. Semi-auto only. All to keep the US BATF&E happy. Loses a lot in translation from the original, but it looks the part.
The upside is that it's about the best closed bolt conversion with which I've ever dealt. Good trigger pull and the bolt cocking force are both outstanding. Reliability has been 100% and accuracy is good if you can figure out a way to hold the dadgummed thing steady. Not a practical piece, but at least it hints at the original design's utility value. Heavier than a M1 carbine and slightly less powerful. But as a SMG, it was quite good.