Carlton started a second series with A in 1966...
B in 1967 C in 1968 D in 1969 E in 1970 F in 1971 G in 1972 H in 1973 A in 1973 (on some nontrivial quantity of frames) WxNNNNN in 1974
Hilary, I think you might be getting the 1967 year from the http://www.carltoncycles.me.uk website. I've complained about that numerology to the website creator, jerry mortimer, many times. Jerry has made no effort on his part to fix errors in his numerology.
I am in agreement with Sheldon Brown on the above numerology. Below is an official letter from Raleigh that documents the WxNNN numerology.
http://www.bulgier.net/
I have never found a 1973 Wx3nnnnn bike on ebay so the belief is that the Wx4nnnn lettering scheme started in 1974. I have emailed about 20-30 sellers offering Raleigh International and Professional models to determine the serial nubmers and match it to the badging.
For Jerry Mortimer to be right, every catalog on http://www.retroraleighs.com and also http://www.bulgier.net would have be mis-dated before 1974.
I myself have a 1972 catalog procured in November 1972 by me at a bike shop. My catalog matches the 1972 catalog on retro-raleighs so I know for certain that retro-raleighs is right and mortimer is wrong.
I also have photos of a 1971 catalog (not on any of these websites) and one all-original 1971 bike, F serial number (1971), 1970 campag parts. I emailed 1 or 2 people on ebay claiming to have 1972 bikes, and I found that their serial number was G, and the badging was a step forward from my all-original bike.
So we have correct yearly dates for the Raleigh/Carlton catalogs. And the bikes that match the catalogs have SN#s that match our numerology. And therefore the numerology starts with H=1973 and works back one per year, resulting in A=1966.
http://www.sheldonbrown.com/
Jerry Mortimore is/was wrong.
- DOn Gillies
San Diego, CA