When I first got into Zs in the early 2000s, this is what many cars that came to market were like - UK, older "restorations", reflective of the time and the values of the cars as they had been from the 80s on up. So, complete, usable, but with doubtlessly previous repairs and refinishing work done to a budget rather than getting the details right. Prices in the 4-8k range.
What that means today is that something like the car being discussed, while "okay" isn't going to live up to modern expectations of quality, and despite all the talk of 35k+ RHD UK cars, such a car's market value is going to be affected by the reality that bringing it up to standard means 20-30k (or possibly plenty more) lost in work if you can't do it yourself. I.e. you won't get your investment back, if that's a consideration.
Low 20Ks might be reasonable (IMO should be less considering the above), backed with a well-equipped garage, good skills... or strong cash reserve and/or large credit card limit!