I rebuilt mine this time last year with all genuine bits from sandifords, eg mains, seals, piston kit, gaskets total bill was £514 most expensive part was the crankshaft they don't do a conrod kit so had to have a new crank @£195, barrel replate was £140
the rebuild was worth every penny in my opinion they are a fantastic bike love mine to bits
as mentioned in a previous post http://www.langcourt.com/page16.html for replating barrel