I've just changed the carburettor flexi pipes either side of each carb. They only looked slightly ropey from the exterior but my word they were in a bad state. Both the carb to head rubbers were split really bad but the split was hidden from view due to it being at the back, nearest the enginend. I assume the engine heat had something to do with this side perishing more.
So glad I've done these before putting the R65 into service.