Just picked this up off CL. I'm a sucker for chrome lugs. The headbadge would place it between '67 and '70, right? The serial number, N5775 is on the left rear dropout. N would be for Nottingham but Carlton put the numbers on the dropout. I haven't found any evidence of chrome on the rear stays but the paint is pretty thick back there. Haven't seen a bike with chrome lugs but not stays.
It's been ridden hard and completely rebuilt and ridden hard again. Lots of different components. They seem to be well chosen, though. The hub shiners are trick. I'll dig into the BB really soon here and figure out the threading. It's got just slightly steeper angles than the green Supercourse in the background but lots and lots of other similarities.
What do you think? Grand Prix? Grand Sport? Couldn't be a Competition, I just don't have that kind of luck.