Okay, so the plan now is I get the towbar fitted, buy the trailer and then get back to you.
 
The gearbox was perfect after the repair. Everything went in smooth like butter (engine off clutch depressed) so I am still hoping it was just the reinstallation that has caused the problem and and possible new damage.

Thanks for your help sofar. 

Thanks look forward to that Fran.

Great to meet you this evening Matthew. Nice looking buggy and looking forward to seeing it take shape. The sooner you can get it trailered for a health check the sooner it'll be on the road. Cheers. Fran

Thanks again.  The installation of the Thule tow bar has been a success. I am going to make a post about trailers in a new thread.