As if you're going to be able to get official replacement parts from the Soviet factories. I have to assume the person buying this is going to register it as some kind of experimental or historic aircraft where the regulations are looser. It's not like he's going to be carrying passengers at least.
China produced a copy of the MIG-17 (J-5) until the late 1980s, and both it and the MIG-17 were widely exported. I wouldn't be surprised if parts were available.
Was the power plant used in any long lived civilian applications? That could greatly help the parts situation. Still, for the airframe you're probably best off machining your own parts. You'll probably be able to make parts to tighter tolerances than the Soviet factories.
According to Wikipedia, they're still used as snowblowers and ice melters. And this engine isn't unique to the Mig-17, it was used in the Mig-15, IL-28 and Tu-14 bombers, and is one of the mostly widely produced jet engines in history.
Experimental exhibition has different rules from other categories, but the FAA also allows for owner produced parts on certified planes. https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
Most warbirds are not experimental so you can't just build whatever you need and slap it on. Sure you can convert to experimental but you still have the high maintenance costs (FAR 43.1(b)(1)) is the section of law you should google)
Edit: someone looked up the tail number and this one got lucky but don't assume you can just slap your own machined parts on a P51 or something without jumping through hoops.