Right, all done.
Phoned the garage where the 2 services had been done - no other history, and they were surprised, but could offer no explanation.
Went to the dealers this afternoon, and said I wasn't happy, and asked if there was any way we could work round it. They offered a warranty (RAC), but after reading the small print, claims wouldn't be honoured without 'recommended servicing'. 20 minutes discussing that, and I said I still wasn't happy, despite the manager giving me a '100% guarantee' that servicing had been carried out.
I went for a little walk while they tried to work it out.
Got back, and they had faxed the previous owner (Lloyds), who had fax-replied with a computer printout detailing all services, where and when they were done, at 10,000 miles, including the two in the book. Also had details of all repairs - windscreens, tyres, light bulbs. Nothing mechanical seems to have failed. This would be a pretty elaborate fraud to perpetrate in 10 minutes, so I believed them, and bought it.
On top of the original agreement I got the full history and 12 month warranty (which isn't too bad - includes climate control for example). I would say I effectively paid £6800. Not as good deal as a couple mentioned above, but not too bad.
Drives like a dream, absolutely immaculate, not a mark on it inside or out. Took it to 90, solid as a rock, stuck in traffic for an hour, not a murmur.
I realise this was still a risky buy, but I'd like to thank all of you that took the trouble to reply. It gave me a lot more confidence in a situation where I didn't know what I was doing, and I got a better deal because of it. More importantly - I'm a lot happier. I owe some people a drink - if you're in Sheffield, let me know
Cheers, Rob