I too bought my first Nigel Dean, a red Tour Ace, in 1992 in that Leeds shop. My sister bought one too, by coincidence, in London at the same time. I rode that lovely bike until a respray in about 2010, and then wrote it off after hitting a Alfa Romeo Spider in Chepstow, on Lejog in 2012. So I bought a Danube, the same frame but very slightly different kit, and ride it most of the time. For good measure I also found a golden yellow model, barely ridden in 25 years, and might be tempted by a ND mtb if I see one. I have two spare 531st frames if anyone needs one.
There is to be a VCC article on Nigel Dean, including a current interview with him, and I believe Geoff Duke (above) has been contacted. Thanks Geoff for that. Keep the ND name current - they are lovely bikes to ride. Simon
(If I could work it out I'd add a picture of one)