Hi, Fred
Yes, I think your correct on the 240 power in England, But it was running in the US so it may have isolated input power or transformer.
Check the power cord, Dose it have 3 conductors 1 to gnd. other 2 isolated from gnd. may be a clue.
The 50hz to 60hz isn't a problem, PM'd my phone #.
Thanks, Chip
Edit: looks like good drawings.