At the moment I am browsing thru about 200 digital editions of the British Go Journal, starting in 1967. I will share some impressions with you. In chronological order.
(This might take some time.)
I think they’re just variations on the same joseki.
So 83, 83a, 83b, 83c are the same up to a point, and then they split off into different variations. C4 is when Black blocks the other side to 82 and it gives different continuations.
The British Judo Council was founded in 1958, five years after the British Go Association.
Just the BGA affiliated to the European Go Federation and the International Go Federation, the BJC affiliated to the British Judo Association, which is a member of the European Judo Union and the International Judo Federation.
Wikipedia says:
The BJC have a more traditional outlook towards Judo than is generally the case in Britain. The traditional white judogi is preferred over the more recent blue judogi that was introduced for international competition. Etiquette is more rigidly adhered to than is often the case in more sport-oriented clubs and organisations. The BJC stress the importance of kata, a view that is not shared by some other large organisational bodies in the UK.
I think I some people have suggested a version like that too, playing several moves while it’s your turn and then the next person on your team gets a few moves etc. Does seem interesting
I feel bound to point out that quite a few of the recent excerpts have already been posted in the thread, as one would see if one read the thread through.