Heard from the garage this afternoon, they found significant wear on the input shaft bearing and selector forks. Looks like there are three bearings and two selector forks needed which is going to cost £160, the release bearing is included in price. Apparently the clutch showed minimal signs of wear, I just said replace it whilst its stripped, for peace of mind. As for the leak, they said something about the driveshaft not being installed properly which was causing quite a leak, so not the gear selector. I'd keep yours topped up as such as you can.
They've been really good to deal with actually and if the costs work out okay I'll head there again when the cambelt is due.