Hmm, well, bad news and maybe better news. RS have admitted that they won't actually be getting any more because they are no longer manufactured.
Better news, Mouser UK appear to have actual stock
https://www.mouser.co.uk/ProductDeta...fu%2FVL1AJXw==
...although I notice their re-order quantity is zero, so once they are gone they will be gone. I've ordered a small number and we'll see if they actually turn up.