See http://www.fiftiesandsixties.co.uk/ .
Lots of retro UK stuff, including a description of "old money", which is basically simple:

4 farthings/pence,
12 pence/shilling,
5 shillings/crown
20 shillings/pound
21 shillings/guniea

AFAIK, the UK was a bit slow to let go of what Americans cosidered gawdy styling.