Well after not running it much due to these nasty noises and considering selling the old girl I managed to drain the battery down to absolute zero. Not even enough to lock with the central locking...
Got a jump start and decided it a good idea to refit one of the lock barrels. Good job as it went dead again over a week or two sat idle....
Found those battery booster pack things don't work with a dead dead battery...
So managed to get in there with the key and fished out battery, exchanged battery booster for a charger and seem to have resurrected the battery. Got the car to a pals house and had some spanner time on the engine mount.
Took the engine mount off and fitted a new one, which cured the vibration in the cabin. Not the squeak.
Worked out the squeak was the pancake pipe swinging around and rubbing on stuff. Guess due to the saggy engine mount. Fixed with a washer.
Car is running again and I'm quite relieved it didn't sell. Had some really silly offers.