Sounds dodgey. But I can think of a couple of theories to cover it (other than scarab making 2 #153). Theory 1. Ebay car is a fake and somehow got a scarab id plate, as red car owner claims to have original scarab paper work. Theory 2. Ebay car, is a scarab, He sells the engine after he decides it's not powerful enough. It gets put in the red car, which gets a scarab kit makeover. And since it has the original #153 engine (They had numbered intake manifolds apparently), the PO is able to get a replacement tag from scarab?? and maybe copies of paperwork? I'm wondering what details are on the paperwork. If it lists the Nissan chassis number as being the same as the red car, then thats the original one. If it list the blue cars number then thats the original one. If it doesn't list the chassis number, then nothing can really be proved by it. Oh the shenanigans that PO's will get up to. I'll bet on the red one. MEZZ. You could report the car to ebay as it's may be being misrepresented as an original scarab, when possibly it isn't, and send them a link to the other #153 on cardomain. Though whether they would actually take any action is anybodies guess.