In reply to Mick Ward:
Many thanks for replies. Perhaps I should have mentioned that I'm Irish and thereby hold an Irish passport. However it didn't seem germane to the enquiry.
To Rick: I've thought of coming back but it does seem extravagant to do so merely for more relevant insurance, e.g. increased cost, lost working time and approximately twice the carbon footprint.
To Jim: I've got a GHIC and a SIP card and am in the Spanish medical system. Am also in very good health. More a case of say getting hit by stonefall and being in hospital for quite some time.
To Climbing Pieman: Thank you for the Insure and Go tip. For some reason, have not come across them, despite trying lots of recommendations from the British Insurers' Brokers Association. Will give them a go.
Mick