I picked up a set of the Allballs low stiction seals a while ago as better replacements. Can't remember where online I got em but you could look for them.
i read to replace the oil seal and the dust seal, bike bandit has both but its 60 bucks for both, frick that. thats a triumph part. searched for after makret and they dont have thruxton after market seals on bikeripoffbandit.