Update - I let More Than's follow-up calls go to voicemail for a week or so, then spoke to them today. Got a further discount for having my home insurance with them. For this year I'm now paying £411.52 a month for both Henry and Sugar the senior cat. That compares with £780 on my previous policy, like-for-like lifetime cover.
I know it will go up again next year, but for a saving of that much, worth shopping around!