Check out Photofusion in Brixton, they have community darkrooms and a gallery, I've exhibited there. LIP (London Independent Photographers) has I think morphed into something else, they had many darkroom workers. Maybe clubs are the wrong approach as they are usually affiliated to the PAGB and almost 100% digital, but there are collective darkrooms. Have a look at Ilford's Local Darkroom scheme, there may be something near you.
Over the past maybe 15 years I've given talks to various monochrome groups like The East Midlands Monochrome Group, North Yorks Monochrome. Cotswold Monochrome, etc. but while I've only shown analog work almost every member is 100% digital.
You would be better joining a Facebook group like UK Film Photography, and ask there.
Ian