So this board isn't completely dead/deserted
I've ended up getting another one, from a second owner with all service records.
I know a lot of people say 7 series isn't reliable, I've had 540, 550, 330, 335 and a 740. It all depends really, when you get a used car that costs a lot brand new you can expect higher maintenance/repair bills.
For the last 3-4 years I've had SUVs only and what I saved in repairs I paid extra in fuel (my last Navigator had an average of 16l/100km, winter was around 20l/100km in the city).