Walter,
My car is what is known as a “ Tourist Delivery” meaning that it was ordered from a dealer in Sydney to Australian specs and delivered to the buyer in Germany direct from the factory. They then used it for a holiday in Europe on temp plates and returned it to the factory for delivery to Australia.
I suspect that is what you have in a similar fashion, that is, the original owner, knowing that he was going to take it home, ordered it in London to US specs and took delivery either in London or Germany then at some future time shipped it to the USA.
A bit like the US military stationed in Germany could order one to US specs, take delivery in Germany then take it home at the end of their tour of duty there..
Garry