Nothing in the UK refurb store and no 21" iMacs yet unfortunately - though there haven't been many of the 21" 2012 models in the UK recently anyway.
Looks like I may just go for a new one while I can take advantage of the interest free credit offer. Also, annoyingly, you only get a mouse with the refurbs and can't swap for a trackpad.
Now I need to decide whether or not to upgrade both processor and RAM, just the RAM or nothing.