I have read this thread with interest.I feel it is important to keep these traditions alive, and writing them down is one way of doing this. However, these need to be full and accurate descriptions if they are to help future generations to maintain the culture.I would therefore like to add my humble expertise to existing postings.

Micca,
I loved your post. I feel however that you missed a vital piece of the British male national costume.You said,

"Based only on a cursory observation of its widespread occurance the English national dress (male)it must be Jeans (scruffy)or extremely uunflattering shorts over pasty white legs, T shirt(with slogan or pop group or football club strip).This seems to be the most widespread male attire in this part of London"

You forgot to add........ sandals with socks!

Walkabouts verse,
Your description of the female costume was almost there, but I feel it important to correct an important omission. You said,

"Last night, driving through Dulwich, I found myself behind a woman cycling. Cropped jeans, lying low on the hip. Above, a thong bisecting exposed upper buttocks. Above that a skimpy top waist length.

Don't forget the importance of the multiple piercings ("home made")through such parts of the body as eyebrows, lips, tongue, navel ...........and,in a case I saw this week, the back of the neck.
I still have bad dreams about a thong I saw a young girl wearing at Party in the park a few years ago. The visible part was......A CHAIN!Now that is true dedication to the living tradition!