There is a 64 Cooper S on Bring A Trailer (
https://bringatrailer.com/listing/1964-austin-cooper-s-2/) from the good people at Mini City in Rochester NY that says it has a matching key for both doors and ignition. It made me curious, although I only have one car to judge things by.
I suspect they're closing shop, sad for me to see as when I bought my '63 Cooper in 1992 it came with a Mini City catalog. 2 months later I was in the USVI and was outside the shop in Christenstead where Laurie was checking out swimsuits chatting with her father in law about Minis as he was wearing a Mini City t-shirt. Laurie sent Grover Mauer to me when he was building his car in 1996 as a local Mini owner to help with his build.
It's a small world.
Cheers,
Jim, Diana and Jimmy
Too many toys, not enough room.... soon