Tracking the ownership of a Daimler DS420 now in Canada

[555ttg]

I'm not sure if their is the right forum or what, but I am trying to help a friend discover the origins of his DS420. It seems it may have been a Royal car, but he's not getting anywhere. VIN# is 1M3523BW it was registered VJM684S when it was imported from the UK, but this may not have been it's original number plate.
Any help greatly appreciated!
Phil