I had a '69 Triumph T100C - single-carb 500cc
twin - that was SAE on
body parts, metric on engine peripherals and drive-train, and the engine
itself was all Whitworth. I spent more on tools than I did on parts
with that bike.
My Myford Super 7 Lathe (about 7 years old) has a seemingly random mix of
Whitworth (BSW), BA, and metric screws. Mind you, you do get a toolkit
(spanners, allen keys, oil gun, C-spanner for the headstock bearings,
etc) with it, so it's not so bad....
-tony