Take a good look round the vehicle and see how unmolested it is. Are all the bits present in the engine bay such as the Firewire frame in front of the radiator? How much of the turret contents are present? They are awkward to find if you want to do a full restoration.
As with all K60 vehicles, the heat exchanger is the weak point. Look for water in the gearbox oil or oil in the radiator. They are unique to the Abbot, impossible to get hold of as spares and very difficult to repair, not helped by the fact that the entire pack seems to be built round them.
Check for overheating, the fans and their hydraulic system are also unique to the Abbot. Other than that, check the battery charging voltage as dead regulator boxes aren't uncommon. Some Abbots suffered from hull cracking but as it's under the pack you won't be able to see it. Oh, and take it for a decent drive to check gears and brakes!
Andy