Getting back on topic, I have to agree with the approach that these are old cars now and the chances of finding a low owner, garage queen thats for sale are low - not impossible, but low.
Remedial work such as waterpumps etc are part and parcel of owning these vehicles, but then saying that, of the 5 Zs I’ve owned, I’ve never once had to change a waterpump.
My current Zed was bought on low miles, medium owners and with limited paperwork. Hasn’t put me off because underneath all of that there’s a good 18 year old car.
If you have the time and patience then you’ll probably find what you’re after (most likely on here), so good luck!