My dad has a screwdriver just like that too, no idea where it came from.
As for the brakes, it won't have been the dead servo warping the discs. Without the servo you can't brake as hard (as you know) so you won't get as much heat into the discs to warp them. Most warped discs I've seen (admittedly not many) have been down to dodgy calipers so one side of the disc did more work & they heated unevenly.
Im sending off for new Calipers so hopefully I can nip this in the butt
I am also suffering from starting issues once the car has warmed up
Jim suggested he thinks its fuel vapourisation vapour lock I do no wonder if my return pipe is failing as the car always stinks of fuel
Think its time to take it off the road and get the house in order.................................