I would think that guy is going to jail lol. Yes I actually took the time to read the entire add/description. It gets really shady talking about he has vin tags for different colors you might want to paint it.
Not sure about IL, where the guy is located but it's illegal in most states. That's a lot of Vin tags, change a LeMans to a GTO and will install tags for more money. Looks like a classic car chop shop.
As soon as he said "correct rivets" he went illegal. Altering a tag, or anything related to a tag is illegal. Cutting the metal a few inches away from the tag and welding it back into another car is a VERY gray area.