Final gearbox parts have arrived, so reassembled the gearbox this morning. Pretty straight forward just follow the manual, only things to watch out for is the countershaft 5th gear spacer has an oil hole so I marked it with a sharpie to check alignment on the shaft and the circlips have to be assembled with the sharp edge facing the correct direction, both detailed in the manual.
Fitting 2nd gear back on the shaft required the press again, I gently heated the gear with a hot air gun then tapped it on to ensure it was straight then pressed it the rest of the way using an old socket. The manual says to use loctite, wtf, its so tight loctite would just be pushed out of the way, so didn’t bother with that step.