I have asked back to Poland and got this answer:
Poland sold in the 1960s a production line for steel cased 7.62x39. The cartridges here in Question look similar to Polish ones but the laquer is slightly different (“stretched”?). Poland never crimped primers and the case head is pretty much rounded at the edges unlike Polish cartridges.
Later on French machinery for brass cases was purchased.
Poland never made 12.7x108 steel cases so the origin of the Egyptian steel cases must be a different one.
I hope the information above is correct and is shedding some light on the subject.
My thought on Egyptian 12.7x108 steel cases is so far:
Steel cases were so far only known from China, Pakistan (with Chinese background I think), Czechoslovakia and Romania so it is likely that one of these countries is the supplier of the production equipment. Going by the green color it might be China then.