i assume you mean a construction of a stock itself and hinged trunnion that will connect the stock to the receiver?
so trunnion would be most machining-intensive part. i see no way of fabricating it it without a vertical mill. that is if you wanna go for a clone of the original. as well you also might need a lathe to machine hinge axis pin, latch pin and locking piece.
although i can see how all this can be accomplished with just a bunch of bent sheetmetal pieces all welded together. For tools some pliers, vise, regular stock angle and round steel, drill, welder and dremmel or hacksaw and files. it won't look as pretty as original but it'll be functional. interesting challenge if you got some time on your hands.