So, the banana icecream turned out rather more like banana kulfi, which isn't that much of a surprise given that the principal ingredient was condensed milk. It's good, if slightly on the sweet side. I think it would go well with strawberries, particularly the less sweet ones that are available right now at the very end of the berry season.
I had rather more success with a malted chocolate icecream that I made at the weekend and which I adapted from a recipe for dark chocolate icecream that's in the new Morfudd Richards book on ices. I replaced the dark choc with milk choc, and substituted Ovaltine for the cocoa. I halved the quantities (to avoid uncontrollable gluttony and so the mixture would fit in the icecream maker all at once), and presto! Delicious icecream, the taste and texture of which improved after one day.