Tackle, the stens are mild steel, the stock tube is stainless steel, for some unknown reason. I took one to bare metal, heated the parts till they were straw coloured and quenched them in hydraulic oil. As stainless won't react to that, that was heated till it was almost white hot which blended it in a bit more with the rest of the gun, then had to oil quench the mild steel parts that are attached to it. Came out looking pretty.
I would say the sten is the best starting point too. You've at least then got the mag well and a mag, receiver, shroud and barrel done. It won't be 100% but you'll get it damn well close.
Also don't be tempted to make any of this out of alloy. Mild steel is nice and easy to work with. Have you got a bench with a vice and a handful of tools? A decent saw, hammer, metal drill bits and a couple of files will see most of that sorted. I think the hardest part of that build is the shoulder pad on the stock unless you cheat and use an mp40 piece.
And I'd definitely not paint it, heat and oil will give that a very realistic finish.
