...additional...having had a good look around with a magnifier and torch...

the damage seems to be where the power leads join the board (from the 'on' button on the casing). I think someone has tried to solder the leads back onto the circuit board - and clearly failed!

Is there another way to get into the power system?

Or can I 'hot wire' it to start in another way?

I'd really like to get this up and running because the case/screen/ everything else is in pristine condition, and looks like it was damaged very early in its life.

any help, of course, greatly appreciated.