The engine is back from TecMoto - I think they've actually given me the wrong one as the one I dropped off was black and this one seems to be silver!
They've done a very nice job in sorting it all out for me and the alternator nut has been LockTited, torqued up "and then some" to ensure it doesn't come undone. Every single valve was spot-on - not bad for a 33K miler!
I'm now off out to the garage to start the rebuild, so I may be some time*.
* some of you will obviously be pleased to hear this