That sounds like the best of all outcomes. What a result!thought I'd update the thread as I've had a good outcome. The seller has offered to pay for the retro-fitting of the A/C and I've agreed with Julian at Overland Cruisers to do the work with his A/C specialist. I'll be dropping it off tomorrow and when I pick it up next weekend it should have an (almost) brand new A/C system.

Hats off to the seller for rectifying their error.