Sir_Dave
ClioSport Trader
Not everyone has a mothers, sister, brothers, great aunty twiced removed mechanic in there back pocket though so id rather buy something where someone else has forked out for the work.
Tbh, i'd just buy a 172 that needed the cambelt doing (for £500 less than the others), then pay JMS £500 to do the cambelt.
Some proof of where it was done would be ideal, as you said not by any old monkey.
This is the risk though, even Renault have been known to bugger it up. I'd only want a cambelt being done by JMS, Fred, Birchdown, etc. Its pivotal to a cars health.