Thanks all for the nice messages of support - they’re well appreciated!
Good news: I’ve worked through the night - aided by the redoubtable Andrew VK3ARR who is now taking a well-earned rest as I write - and have ported the entire codebase for sotamaps to a new server run by the MT IT department, thus doing away with the old hosting company and server.
Also transferred the latest tracks data and associations/regions/summits data to the db on the new server.
Last step was pointing the DNS to the new server - you should be aware that this last step will take some time (up to 4 hours, depending on the breaks) to propagate around the interweb.
So, it should be business as usual after a short waiting period. As with all such (hasty) transfers, errors will probably be encountered until I’ve “ironed out the creases”.