If your oem seal is leaking bad, it is most likely because the seal is dry rotted and cracked... or the mainshaft races outer drive sprocket seal surface is deeply grooved through many years of use. NOS oem seals are still very good if warmed up good before installing the sprocket onto the mainshaft. I now heat them up to roughly 175 degrees before installing them. The heat seems to make them plyable again.
That is interesting. Do you heat them up in oil presumably?
Still would like to find a standard seal as parts take 3-4 weeks to get from the US to the remote part of Oz where I live, but we have a local bearing supplier with a good stock of lip seals.
I am sure my old seal has suffered some rot - it has been in there since I restored the bike 38 years ago.
Just pulled her out of my late father's shed recently and am trying to breathe a bit of life back into the old girl, on a really limited budget both time and money wise.
Not sure how to post pics but I'll give it a try: