The South West London DA is a thriving local group of the national Cyclists Touring Club, with several local sections.
The DA website is http://www.cyclingswlondon.org.uk and their DA Blog.
This website contains archives of the DA: primarily from the DA magazine, the Sou'Wester, but also runs lists and will contain photos and anything else I can get my hands on.
Over the years since it was first formed in 1948, the DA has been the parent organisation of a number of local sections, some of which no longer exist, these include:
Beginners: 1995-to date
Cheam & Morden
Downlands
Family
FNRttC (Friday Night Ride to the Coast)
Intermediates
Midweek Wayfarers: 1980-to date
Mitcham & Tooting: ?-1986
North Cheam
Saturday
Saturday Afternoon: 1949-?
Wanderers
Wayfarers
Wimbledon
Youth