Not sure if there’s any way to check if it’s been clocked (maybe some sort of dealer level scan tool?) but there’s a very high chance it has been as clocking is rife in poorer countries, particularly on higher end cars. If you could prove it had been clocked, that would give you a stronger case.
Regardless, 20k miles on roads like that is the equivalent of 100k+ on UK roads: there’s a reason why so many people in Africa drive Hiluxes and Land Cruisers as modern sports cars just don’t hold up to the abuse.
As others have mentioned, a lot of the paint issues look like evidence of a poor previous repair to me: it could well have been crashed to the extent of a U.K. write off, but bodge repaired with cheap labor. A friend owns a body shop in Mexico and you wouldn’t believe the state of some of the stuff they repair in terms of crash structure / integrity and that’s without any bodging in terms of paint, filler, panels etc. Chances are, if it looks bad on the outside, it’s far worse underneath.
Even if you can’t reject it, I’d get shot of it ASAP even if you end up losing money.