Realised yesterday that the passenger seat wasn’t raising the front of the squab, motor could be heard working so I decided to investigate.
Turns out that the gear has lost a couple of teeth;
I think this must have happened when I had the 6’3” son in the seat and he dropped it down to stop his head denting the roof.
Once I had stripped the gear box apart it became obvious what the problem was.
I managed to drill 2 holes into the root area where the teeth were and insert a couple of screws into each, dremel cut off wheel dealt with the extra length and rough shaping finished with needle files. And viola it now works, a bit lumpy one way but at least the wife can rise to my level.