Hopefully this pic shows the sealhousing

Thank you Stuart for your thoughts re the Versatiller, judging by the diameter of the bearing housings I would go along with the needle bearing theory and like you I suspect that the seal arrangement is contained in the press fit steel caps that also form a shield on the ends of the bearing housing.
However as the machine is not mine and the owner rather likes it I am not intending to get into a situation where the machine becomes beyond repair until such time as the oil leakage becomes intolerable. Since my first posting I have tried removing the seal caps in the hope that maybe they contain a standard lip seal but they are very tightly fitted and to carry on with this route would probably have destroyed the seal casings.
During my investigations I did notice that some oil was leaking from the joint between between the two halves of the chaincase, the cause of this was that most of the bolts and nuts were slack so hopefully tightening these will help to reduce the leakage.

If all else fails there is always the option of removing the oil that is in there and refilling with a semi fluid grease.

Thank’s for the tip off re Paul I shall send him a message.
Ray.