The 'F' series was the original Varicam and the 'H' was a later and slightly upgraded version, although I think the upgrade was simply because there was better tech at the time not a significant overhaul of the camera. From what I was told a long time ago (that's code for "I may be remembering this wrong and steering you in the wrong direction") the only differences between a Varicam for Europe and one for the US was the electrical wiring inside as there are different standards and codes.
Oh, and the Varicams sold in Europe appreciate soccer.
Thanks for trying Chris - I think I've managed to 'Sherlock' it out! For some strange reason all the English operating manuals on line that claim to be for the 'HE' version are actually for the 'FE'! I managed to find an Italian 'HE' one and comparing the 'VP' manual with them both, it clearly is equivalent to a 'FE'. The main difference is apparently that the FE (and VP) have 10 bit processing whereas the HE has 12 bits.