Have since thrown another new seal at it and it is still leaking oil, couple of drops on the driveway after a long drive.
Was pretty careful installing it last time, polished the output shaft with fine wet and dry sandpaper, lubed everything up before install, held back the cover that sits on the back of the gearbox so i could watch the lips on the oil seal when putting the tail shaft back in... running out of ideas

Vaguely remember when i first bought the thing they had to do something with the rear extension housing (which houses the rear oil seal) as it was leaking somewhere... think it was a bit of a known problem?
Anyone have any tips on what it could be or better ways to install it the seal/output shaft?
Cheer's, Ben