I have to say, when the noise first started, it didn’t even cross my mind that it was a gearbox issue per se.
It just didn’t seem that sort of noise - the rattle seemed to emanate from the shifter area, not from down inside the gearbox.
The only noise is the stick rattling. So I dunno, wishful thinking maybe but I’ll keep my fingers crossed.
Incidentally, I’m away at the moment so unable to check the bushes and cup, but when I do check I’ll post my findings.
Many thanks again all, much appreciate the help and advice. 👍