Counterfeit Cars on FABO!!!

I'm confused......... Putting sweptline trucks together, I have swapped cabs because of rust in the body mounts, the VIN went with the cab, the truck became the new VIN on the new cab, is this somehow wrong? Just like my beautiful 70 Dodge actually is a 69 with a 70 Front end and trim?? Not sure how building vehicles out of parts is somehow wrong, am I missing something?