Hi John...welcome to the Forum
Being as temperatures are a lot hotter where you are compared to the UK then I imagine a water pump failure would be quite catastrophic to the engine.
Maybe worth running it up with a new pump and belt fitted to see if you can determine wear and any resulting issues.
Also, maybe worth putting a Boroscope down into the cylinder bores to look for scoring or similar marks from seizure of excessive heat transfer into the cylinders.
If all else fails then another engine but at least you've got new belt and pump to swap over to it
Keep us update on how you get on with this project
Cheers Trevor