Mght need to SKF Spedi Sleeve that cam shaft. Mine weeped for ages after a few seal/gasket changes until i Spedi Sleved it and finally stopped. With These old bikes wouldnt be a bad idea on all sealing surfaces for a Speedi Sleeve.
Will keep that in mind but I think this is just a case of me removing the seal and perhaps damaging it. The shaft looks fine. I will try a new seal and see what happens.