I just thought of a third contender to my list, George Daniels, CBE, DSc, FBHI, FSA, AHCI (1926 - 2011), watchmaker and horologist extraordinaire who invented the co-axial escapement which was the first major innovation in watchmaking since the lever escapement invented some 250 years ago.
To sit and chat with him as he explained the tortuous years of struggle mixed with failures and successes until he got it just right would be marvellous to me.
I'm currently saving up to buy an Omega with his co-axial movement and once purchased will be a very much prized possession of mine.
Regards,
Jay.