yes...in addition to what normanack said - I was on the CL Club's website today and there is an article that was written by Paul Bradshaw of GFF about the CL - it shows the difference in the lines.
Here is a link to the article with pictures of the lines from GFF
http://www.creamlegbarclub.com/22-history-of-the-cream-legbar-in-the-usa
Regarding the A, B and C lines -- it provided everyone in the USA with a lot of genetic diversity for healthy chickens - however in the UK, in 1987, the CL from what I can find out was pretty near extinction. Outcrosses at that time and subsequently may have introduced a number of recessive genetics that only came to the surface when the various lines were crossed in the USA. Hence - the recessive white Cream Legbars appeared here, and the one(s) that didn't lay blue eggs..etc. some of the spangles on the breast feathers etc. that are not 'to standard' -- Some that didn't have crests....it was all a stirring of the genetic pot. It seems that now after the 2010 imports and the subsequent 2011 release to the public of the birds.....we are seeing a much more settled and uniform Cream Legbar.
HTH