The driver's seat back rest moves about 1-2cm back and forward in the 3 lean postitions that are comfortable for me.

All the others have less than 5mm movement and the passenger seat has 1-2mm movement at most.

It appears the release and locking mechanism must be worn, is there an easy fix for this or am I looking at a replacement seat from somewhere?

It's not slipping between positions but the forward motion is doing my head in when braking hard as it feels like the seat is trying to push you through the window!
