Gear Linkage Gaiter
At the rear end of the gear change cables there are concertina type boot gaiters. Unfortunately they have a tendency to degrade and fall apart, and because they are an integral part of the cable itself, it is not possible to purchase them individually from Rover - you have to buy the complete cable, and then struggle to fit the whole thing!
However, a length of bicycle inner-tube and a couple of tie-wraps will make an adequate replacement.
This is the Mark I
Full acknowledgement to Dieter Koennecke for his original idea.
Unfortunately, it only lasted 6 months, probably due to the fact that it was being compressed severely every time I changed up a gear into 2nd or 4th. The new Mark II has been made of a much shorter length of inner-tube, with the rear most end being tie-wrapped to the white nylon sleeving of the cable itself. Since this sleeving does not move, the gaiter should last much longer.
This is the Mark II