This car is THE reason we no longer sell our build tags to home/kit builders. They are ONLY installed on factory completed rollers and up. It's just too confusing.
Without a chassis number I don't know the details of who/what/when on this one, but I'm guessing it was a kit build by a lot of things I see in the pics...
As for the legality of it, it just depends on the state and their rules at the time. Many years ago, some states WOULD register based on the year of the donor engine, and if that engine is tied to a VIN/Chassis they'll adapt that. There were also some states that would allow the use of the "donor" VIN if a certain % of the parts came from that donor... so it is plausible that one could use drivetrain and suspension as well as some misc. bolt ons and qualify for a % of parts used. Nonetheless, I don't believe there is ANY state that would allow that on a newly built one today.
In this case, being that it is already titled that way, it's probably best to just title transfer it "as-is" and keep you amount shut I suppose...