In defense of the M-76: A local fellow has a one for sale. He has owned it for 20 years that I know of, and he has shot it a lot. He says he has never had a stoppage for anything but bad primers and cartridges that had no flash holes (!!!). I have been there through one session of almost 1,000 rounds. It ran flawlessly. Others I know who have shot it have had similar observances.
They may not be MP-5's, but for stamped, third generation buzz guns, they are pretty good examples of their type. I would buy it if not for my current poverty. If he still has it in a while, I may.
Still voting for the Model 61 Escort. They look pretty well machined, fit and finished. I don't know why they usually don't work.