Re-read Marko's post as well as VUPDBlue's.
Now do it once more.
Marko's numbers are a little of on the current value of a transferable MG42 (more in the range of $40k+ for one), but he's got the right idea. If your intent is to have a
legal and functional full-auto MG42, there's no way to get around the registration process. You can't have it cut and then re-build it. You could set up a corporation in a neighboring NFA friendly state and purchase it as a corporate asset in that state, but you'd not be able to bring it back into IL. If you can't get it legally, don't cut it. Leave it alone for someone who can legally own it, enjoy it, keep it running, and keep it as it should be.
If you just want to have a non-functional display, then buy a dummy gun from BRP Corp. Similarly, if you want a semi-auto MG42, but one from BRP Corp.
www.brpguns.com
DO NOT cut a live, registered, and legal MG42. They are rare, expensive, and highly coveted by collectors. Do not destroy a fantastic piece of history. I was once told by Bob 'Bubba' Naess (probably the foremost expert on MG42's and German machineguns in the US) not to even refinish a true uncut C&R MG42. FWIW, I own one. Mine was made in Berlin about 1943 and (according to the prior owner) brought back to the US by a GI during WWII who later registered it in the 1968 amnesty. When I look at each scrape in the finish, each nick in the metal, every ding in the wood, I have to wonder about the prior (German) owners, the American GI who took it and carried it back to the US and the service it saw before it came to my hands.
To cut one up simply so you could have a display would only be a monumental display of your ignorance. As stated in an earlier post, it would be like buying a classic Ferrari and melting down the engine because you couldn't get a drivers license, or coloring in a Picasso with crayons because it didn't quite match the color scheme of your Lazy-Boy. Once destroyed, an MG42 would be irreversibly removed from the NFA registry and cannot be re-registered, re-built, and put back on the registry later.