##UPDATE##
So! After a chat with the Vets4Pets fellow, it was agreed that they would offer 4 months supply ( 28 x 16mg tabs ) on the prescription but only give me 1 prescription for 1 month at a time. That was Ok. The cost for the whole 4 months 'written' prescriptions was the agreed, £17 for ALL the 4 months.
However, we are now three weeks past his last Apoquel tablet and so far , so good.... very, very little air-scratching and no distress at all. I have had no need to appraoch the Vet for any tablets due to Archie's wellbeing, but we know that he has that remedy 'in the bank' if we ever need it again. He had his 14th birthday at the end of September and is really well and still RUNS us to the first tree to have a sniff when we take him out. All good!! 😁