Ordered a personalised stamp from a seller on eBay. Very happy with seller and result, so happy to recommend if anyone is interested.
(Just to note, it takes a couple of weeks for the orders to come through, which is understandable given the handmade nature; also that this seller is working alone, as far as can tell.)
https://www.ebay.co.uk/usr/britishstampmaker
I also ordered one of these (screenshot from seller’s page on eBay, so this address is already in the public domain):
The stamps are so stinking cute!!!