Let me know how you get on. Annoyingly it is just a shorter shift rod, be way cheaper to get the original one out of the mechanism and then made 2cm shorter and fitted back in.
The indie I use are telling me that part no. is for the GT4 and that if I go for it and it doesn't fit when they install, then they won't be able to return for refund.
I'm sure I've read that the GT4 part is used though.
That's correct, it's a GT4 part. However the gearshift assembly is the same across the manual 981 models as far as I'm aware so it should fit. The part has definitely been fitted to at least one GTS model here on PH.
Yup the GT4 part will fit no problem. I'm going to modify the shaft by reducing it by 20mm rather than purchase the exact same mechanism with a 20mm shorter shaft.