Wow, that's a lot to try to do in a forum post!
I suggest you start with the NOC paragraphs on "The Atlas Hybrids - Parts 1 & 2"
http://www.nortonownersclub.org/history
Also Roy Bacon's books contain a lot of data, although some of it is open for debate as to accuracy.
The Atlas Scrambler, G15CS, G15CSR, G15/N, G15/M, and N15 all used the same Matchless frame with Norton forks, Atlas engine, and Norton wheels. (G15/N, N15, Atlas Scrambler were Norton badged, the others Matchless). P11, P11A, P11A Ranger, and Ranger 750 were all built on G85 Matchless frame, Matchless wheels, Matchless forks, with Atlas engine. There were many details changed during the 18 months of production in 1967 and 1968, and the dates of these changes are very vague and the source of many arguments among owners.
Anthony Curzon is probably the most knowledgeable person in the UK on the hybrids as he has done a great deal of research.
Hopefully this is a start!