not got a photo but the bathroom in my flat must be quite similar so I made you a sketch:
Exactly like that (rad in same place) only mirrored along the long axis, and the door opens outward (which helps) and you have what my neighbour's done to the refurb'd place.
Problem is, with a bath 700 wide, just leave 550 between the edge of the bath and tiles. Fit a bog how you've got it there, but tight for getting in and out the bath.
There is another complication in the ceiling slopes. It's 194cm tall at the far end, same height as me. So the shower head needs to be far enough into the room to give me clearance. Also there's a small window on the wall opposite the door, but at the other side. Where AndyL's put the showerhead... Though his layout might still work with the shower on the long edge of the bath (lived in a place like that, was fine).
I should just give up, pull up the current floor, put in a shallow shower tray and new screen and leave everything else as-is, shouldn't I?*
*something needs to be done, as the floor needs to come up to get access to the top of a lead supply pipe that needs to go.