Hole in one.

Defo a stolen shell. You may only re-shell a car using the old ID if it's a brand new shell, which will have a number and a history that the DVLA can trace. Then it's a points system based on how much stuff you use from the original car.

Using an old ID on a 2nd hand shell is ringing. People do this when they get a stolen shell they can't put back on the road.