I see your dilemma Mike.
You are looking at a heater matrix replacement at some point (as a lot of us are
), new drop links, another aircon compressor and a good deal of work that will cost you nothing except time; the cost of parts for all the work is not all that much in the grand scheme of things.
One fan not working is not the Bitron. That'll more than likely be the relay trio in the fan housing playing up. A very common problem upon which Clogzz has posted.
Otherwise, you have a lot of routine stuff which will be the case for any car.
Fact is, you have a new MOT on it so from that, you know the car is more or less OK and has nothing fundamentally seriously wrong. Any advisories?
I'd try not to be too paranoid about the noises you hear, I know and understand why you are but some XUDs can be quite clattery when cold but if it all quietens down when hot and goes OK, there's not a lot to worry about. Listen to my old 1.9TD or Dad's 205 on cold startup
From my viewpoint, you have a car you have had a good chance to look at closely. Fundamentally, from what you have told us, it's sound enough. If it were me, I'd do the necessary over time and keep hold of it. Once it's well fettled, it'll stay good for a long time. That has been my experience with 3 Xantias, 2 205s and 2 405s to date. Each has cost time an money to initially sort but then one enters a long period of calm when only routine maintenance is needed. None of mine started out in any way up to any sort of scratch, especially my Activa. It came close to a decision to break it at one point.
You know some major (and expensive) jobs have already been done on it.
So, on balance, I'd keep on the basis of evidence you have given. What you really need is for an experieced eye to look over it and offer a second opinion.
Also, no-one ever sells a car cheaply because it is in perfect order. If you sold yours now and bought another, I'd be very surprised if even an outwardly tidy one you pay a good bit for will not need a whole raft of work doing to it to bring it up to scratch.
So yours may not be such a costly gamble as you think. Tax and insurance costs will be the same for any car you get.
From a fundamentally good starting point, which you seem to have there, you can give yourself great satisfaction from pulling it up together. It really becomes YOUR car then. Admiral51 has played this card and is now reaping the rewards.