A full receiver and shroud? What does that mean, you have 4 pieces and need them trimmed, aligned, welded together straight, assembled into a gun, blued, then made to run as a semi-auto?
I'm not trying to sound unsympathetic or negative in any way, just realistic.
I think it is very unlikely that you will find someone to build a semi MG42 for you. Besides requiring a manufacturer's FFL to build a gun for someone else, they are a real challenge, and can take a lot of time to get one to work properly. It's very rewarding when the builder gets his gun together and running right, but anyone with experience knows the difficulties involved, and won't put themselves through that much trouble for someone else, unless it would pay a LOT of money. Most people with the manufacturer's license build stuff that isn't this much work.
This isn't putting together a clone AR, or building stamped receiver AK. It's a serious bit of work in a lot of ways, and the weekend tinkerer who calls himself a gun builder can easily be in over his head.
If you don't think you're up to the task, sell your parts and buy a gun that's already together and running. You'll be a lot less frustrated that way. If it was easy, someone would make them already assembled and ready to go, for a lot less money than they sell for now. Wise Lite is at $5,196.47 for a finished gun. The builder's kit isn't really overpriced for $3,949.99.
It's likely something decent already built will be $4000 or more, or for less than that, it may not even have been refinished yet, and have welds showing and the rails held in with little bolts.
A few hundred hours or a few thousand dollars. You get to decide what you want to spend to get this toy. This is one I personally wouldn't try.