Thank you so much for the heads up! They're as 'rare as rocking horse ...' as an old teacher of mine would say. And I've needed one for a project for ages.

Unfortunately thanks to the EU's new tariff regime it would cost over 30eur to ship it here, but luckily I can smuggle one back from my next trip to the UK...

That said for 4 and 5s - I've not had a problem here (Finland) in literally getting them off the shelf of a local retailer (Partco) for the going rate anywhere else.