Stencollector knows what he is doing, has access to the necessary equipment........
Tiriaq, you give me too much credit and could scare away others who want to build these. I am an amateur. My tiny workshop (at present) is a 12X20 room. All that was involved with making the magwell was a block of steel, an angle grinder, a Record 6" vise, an oxy acetylene set, a mig welder, and a 4lb mini sledge. The lathe too, but that was really for cosmetics as much as anything else.
There are shortcuts that can be made to the magwell. If one can find some tubing that is close to the inside diameter of 1.5", then you would not have to make the tube part of the magwell. That would save a fair bit of time. I think, between the heading to town to buy the metal and then making up the mandrel, and forming the metal from scratch, I wasted a lot of time. I also did not go light, but rather over thickness on my metal and then turned/ ground it down to thickness. As I said before, a person could easily use metal of about 15 guage for the rectangular portion of the magwell, and that would likely be strong enough, and a lot easier to work with.
Make no mistake, if you live in an apartment, and do not have access to a workshop, then you are going to have a tough time building the magwell, or any other part of this gun for that matter. While most of the work can be done with a dremel tool and a hand drill, there is welding involved.
As Claven pointed out, I am parting with a couple kits on the EE. There will be no bolt included (but the extractor is), the change levers will have been welded to semi, and unfortunately the barrels are all nipped. The maqwells have been cut in half with a chop saw, in such a way that they can be used for patterns, but not as a magwell.