[emeritus]

Thanks for the info, Lucien. The plug was in a plastic bag labelled something like "European Plug", amongst the other electrical items in one of those rotating vertical displays that also contained miscellaneous bags of screws, hinges, fuses and other small items. I haven't seen any others like it on sale in the UK.

Rewireable Europlugs used to be (and possibly still are) available in mainland Europe. Here's two from my late brother-in-law's effects in France about 10 years ago, so I don't know when they were made. The right-hand one has an elephant logo and, unusually for continental practice, side cable entry. The left-hand one is by Legrand and, despite its appearance, has rear cable entry. Both are rated at 6A 250V and have the angled Europlug sides. For both plugs, the black base carrying the pins and cord grip simply snaps into its white resilient plastic cover.