Update
I chickened out of attending to the oil leak and returned the Mini to Ben to further investigate the oil leak and to replace the timing cover gasket if required, it turns out that the main leak was from the distributor body. We were only on the island for a few days so decided that it was a job that I could do on my return. Ben kindly spoke to Bill Richards to confirm which would be the best distributor for the engine that he had rebuilt and the distributor ordered from minispares.
When I removed the distributor the drive spindle came out with the distributor and luckily didn't drop off before it was fully removed, the new distributor has now been installed and the car is running very nicely. I will keep a check to see if this has solved the oil leak.
I have also decided to replace the door glass and seals as when we were on the way to the IOW we had a small leak from the passenger window and on inspection I think it has seen better days