I know of the following which have either been on the road in the last year or two, or appear save-able. If you know of any others, their reg or their condition and general location I would greatly appreciate if you added to the list!
HGN 40N Blue (last heard of down South)
OCL 602P A gorgeous deep red (up t'north)
NCL 512P Metalic Blue (Southhampton?)
KHJ 366P A nice period lemon yellow (Hertfordshire)
KNS 935N Metalic gold
PKV 493R White (the south!)
KPA 105P A nice light metalic green (Colchester way)
I suspect that of the 1400 or so estate variants, perhaps no more that 12 now survive...but I would like to be proved wrong and there be more!!!