I'm pretty sure the facelift had a revised chain ***embly which was less prone to problems, if you can afford to wait for a slightly younger car ('06 or possibly '55 -look for the 6 speed box on the revised car). I don't think there have been many instances reported on here of chains actually breaking, but there has always been concern over how long a noisy chain has left in it. As the chain was never designed to be a service item, it's not easy to get at and can be a costly replacement. If it's not noisy you're probably ok. Lots of service history with lots of oil changes would re-***ure me that the chain's not been running in dirt for 129K.
Do a search there's loads of advice for things to look out for 7th Gen diesels. In addition to fumes in the cabin (@Stevearcade's cracked manifold) look for no ABS / VSA lights on the dash, no clutch slip when booted in 3rd and 4th, no vibration in the steering wheel (drive shafts), rear wheels aren't hot after a run (sticking calliper), if it's a tourer with electric boot check it goes up and down under power.