Thought I'd dig this thread up as I haven't been around for a bit.
A quick summary:
March 2010 MOT: 5 advisories and a pass.
April 2010: Spheres re-gassed and two new front tyres.
March/Apri 2011 MOT: not sure on the details but got another ticket relatively painlessly.
March 2012 MOT: pass and no advisories.
Various minor things inbetween, nothing that leaps to my mind.
So, I had an update on 4th September 2012: "Cambelt gone. The camshaft is broken as is one of the cam followers."
Spreadsheet note from owner was that I got this going again 24/02/2010 @ 139658 miles. Mileage as of 02/09/2012 (I assume last fill-up) was 168033, so 28375 miles with a missing tensioner bolt (the one that screws into the monkey-metal bit of the head). I'd left it out with advisory to do it later, as the thread was already stripped before I waded in, and access was poor in-situ to do a helicoil job on it.
I can only guess that the pivot nut had loosened sufficient for the belt to just be under the spring tension and prone to bounce. Following that, the belt jumped and took a few bits down with it. I doubt he'll give up on it, but just in case he does, I've pitched my interest. I quite like the idea of slow, asthmatic, waft-o-matics. Even though I don't need one, I thought I'd get in early so to speak.
I think it would be quite easy either to do the head properly this time (and possibly put the slight coolant consumption issue it's had for a long, long time to bed) or just swap in a cam and follower, to get it a bit further down line.