Thanks Andy and Paul for your responses.

After issues with some ceased bolts I plan to run the MC21 engine through the summer months so I get some riding on the bike.
Then during the winter months when my finances are back on track and the motorcycle world is all quiet I plan to send the RJ4 engine down to Plymouth where the guys can hopefully rebuild and clean it up as it looks a very tired engine unlike the rest of the bike which looks like new.

Will add pictures when it's all back in one piece.
Hope this makes sense.
Cheers, Lamey aka Steve