"Geoff Marshall" writes:

If you them all by train, well it takes 19 hours 20 minutse just to get
round them all!

Does that take into account the fact that you can change from
Piccadilly to Metropolitan at Uxbridge, for example, and avoid the
trip back past stations you've already done? There are another couple
of shortcuts like that, some careful planning would be needed to
figure out the quickest route.