There are no manufacturer’s markings on the cover. There is what looks like an index mark on the left side, but I don’t know why it’s there. Maybe it was used in manufacturing?
The only markings I have found so far are on the magazine housing, “TMT IV”, “40147” and the Israeli IDF property mark.
I understand your interest as a toolmaker in how these covers were made. I don’t know much about stamping parts, so it’s interesting for me learn from someone who does. I do know a little about welding and whoever welded this Haganah cover was very good. Remember, this was done before TIG welding was widely available. The steel is only 0.036” thick.
Here are some pictures of the Haganah cover and a MK3 Sten cover made by Lines Bros Ltd.
As you can see, the Lines Bros cover was made with rear welded. That’s interesting to me because they were very good at stamping.
The Canadians seemed to be quite advanced at stamping parts back then. Their version of the Mk4 Sterling, the C1 SMG, also used a lot of stamped parts. I have been able to duplicate most of the parts I was missing using my small 50 ton hydraulic shop press. The bayonet attachment is beyond my ability to press, so I am making it from two parts and welding them together. Then I will machine it to look like it was stamped.