(25 Dec 2014, 5:09 pm)Dan wrote 4644 was the only one which didn't match up with the list that I'd gathered based on information posted on this forum and photographs on Flickr, but if it's a generic one, it means I've got it right.
Didn't even have 4646 down as having been refurbished - but I've changed it to X26/X27 now.
Arriva Durham County: 4646 (NK05 GWZ) by simply|buses, on Flickr