Georgiansilver:
Nigel....mmmm interesting but was not the Hansom cab made by a cab maker called Hansom? I was given to believe this on visiting Buckland Abbey in Devon. I am of course prepared to be educated on this..does someone have the 'knowledge' needed. (Excuse the pun)

Quite right!
That's why I wrote:
Hackney (then and now) was taken to mean 'plying for hire' and it would be a reasonable error to assume that the more modern vehicle had been named in the same way, rather than from the name of its creator.

CHEERS
Nigel