There are a TON of BJ8s out there now with missing and scrambled plates and identities. In many cases, unless the owner has compared the BMIHT certificate data with the numbers on his car, he doesn't even know that the number plates are from several different cars and that the number stamped into the chassis doesn't match any of the plates or components installed. I've seen many replacement VIN plates that appear to be "home-made" since they are stamped so crudely. There is even a car in a museum in Sweden that has a non-original VIN plate with a bogus number, a body plate belonging to a car 8,035 chassis numbers later than the VIN suggests, and the engine from a third car.
I'm finding from circumstantial evidence that some cars fell into the hands of restorers who weren't all that particular about putting the original serialized components and identity plates back on the car they came off of. That includes some who might surprise you.
I am always suspicious when a seller of a car is reluctant to divulge its VIN.
The BJ8 registry has current and historical records for 7,859 cars worldwide, which is approaching 50% of them originally manufactured. This includes certificates for 757 cars and a couple thousand more with BMIHT data but no copy of the certificate. Consequently, the database allows discrepancies to be spotted easily.
Helping to verify true identities, and to restore the original VIN to cars that have lost their identities or have an error in the paperwork, is a service provided by the registry and one that has been used many times.