Thanks for that. Elsewhere on Wikipedia there is the Merlin XII as having this feature:
https://en.wikipedia.org/wiki/Rolls-Royce_Merlin
...beginning in 1939.
Ford - Manchester UK only got going in 1940.
I didn't realise that Ford in America turned down the job, that must have been Mr very contrary Ford for you!
I must have gleaned that 'fact' regarding the Rolls Royce blueprints being no good for Ford from the History Channel. I do wonder though about how much Ford thinking influenced Rolls Royce and their shadow factories elsewhere in England, where they did use relatively untrained staff to crank out the volume.
Wikipedia only lists the Merlin 32 as using a Coffman starter, as it went into naval aircraft maybe there was a requirement to be able to restart an engine in flight.