|NMR5 (Originally a 1956 Registration) on 1912 Crossley 20 HP
It would appear that this car has somehow gained a registration that matches an old 1900's general identifcation mark (trade plate) that was once used on this vehicle! (see pic below)
This may have occured on purpose with an owner simply using the mark! ...or even by error! ...although back when the car was new both of these would be doubtful as no 3-letter plates were in normal use, so the police would likely stop the car.
It is more likely that it was a registration claimed for at some point much later on in this cars life as an 'original registration for the vehicle' even though it was not. Possibly after a rebuild.
The car only seems to have been added to the DVLA register in 2017, so it is quite possible that it may never have had a UK registration previously to 2017. So it's possible the reg was 'claimed as an original' after being imported.
It could also have been obtained by a number of other means, including; an owner securing the number in 1956 for use on this vehicle, obtaining the '1956 registered' car or a car that had the number on it at a later date, or buy purchasing the number from a dealer, or by fraud, or by error, or by transfer, etc.
However this car obtained the mark it all adds to the car's history and so if you have an extra info on this car / registration mark / trade plate, then please let us know, thanks.