So....What is YOUR opinion on VIN swaps ?

So I'm curious.

Let's say GM Guy buys a GM something or other with body on frame construction. It's toast, but the title is clean.
Said person buys a clean parts vehicle, and replaces the hood. No harm, no foul, right?
What if he replaces the frame? To my knowledge, this isn't an issue. The VIN lives elsewhere on the vehicle, so if I'm wrong, please tell me.

As he progresses, he replaces everything BUT THE VIN PLATE. Does the law specify a certain percentage of the vehicle that must remain original? As mentioned, some vehicles require removing the VIN plate for restoration.

On our Mopars, it's a little different.... unibody cars aren't so cut n dry.