A NIB "Caddy" can go anywhere from 120 to about 185 pound in Europe, in the US people a sometimes willing to part with a bit more for NIB's.
There to old to race in the vintage races ( and most avoid racing NIB's ) and a bit to new for the real collectors. That makes them perfect for the "non-collectors" who just want one out of nostalgia. That's why I have one myself
Put it on Ebay (sell worldwide !) with a minumum of 90 quid and see what happens. Maybe wait a few months though since december is an expensive month for most.