Hello Marc,
I have a few frames and bikes from various older London builders so I recognised the name of Dunning.
Dunning's were a small independent frame builder located in Willesden, one of many such concerns to be found in London after the war producing lightweight road frames which often featured Nervex lugs. I recall Dunning frames have the year of production on the 6 digit frame number - the last 2 digits being the year which can also be found on the fork steerer tube. Not sure about the paintwork but I think I've seen pics of a contemporary Claud Butler with crackle paint finish. Does it have any of the original transfers?
Value wise depends on condition and to an extent the size. From what I see on Ebay and elsewhere these sort of frames from London; F H Scotts, W P Newtons and the like go for no more than £150. The more sought after ones like Ephgrave and Hetchins go for hundreds more but they're the exception. If it is a Dunning I would certainly be interested.
Hope this helps.
Regards
Shaun
