I would tend to agree with others that it's probably not a bad vehicle, as it has a lot of service history with a main dealer. The reason the main dealer probably didn't know about the VCU problem is that by the time it reaches the 70k-100k milage, most owners are not paying through the nose for main dealer servicing. The fact one of your previous owners did, gives some indication that they cared for the vehicle.
If the propshaft is still in situ, and there are no nasty noises in the drivetrain it could be ok, even with the different tyres on it. That was the gamble I took when I bought mine. (I'd looked at so much other rubbish out there, the one I ended up buying had different tyres from back to front. What I did was take the prop off shortly after buying it, and saved for new set of 4 tyres and swapped a recon VCU in. With the prop off, it doesn't matter about the tyres)
Check as much as you can works at the time of purchase, budget for some preventative maintenance when you take ownership of it, and you'll probably have a decent vehicle, and just in time for the nasty weather too!
If the propshaft is still in situ, and there are no nasty noises in the drivetrain it could be ok, even with the different tyres on it. That was the gamble I took when I bought mine. (I'd looked at so much other rubbish out there, the one I ended up buying had different tyres from back to front. What I did was take the prop off shortly after buying it, and saved for new set of 4 tyres and swapped a recon VCU in. With the prop off, it doesn't matter about the tyres)
Check as much as you can works at the time of purchase, budget for some preventative maintenance when you take ownership of it, and you'll probably have a decent vehicle, and just in time for the nasty weather too!