Been wondering about special guests... I can't help with any contacts or hook-ups. However, Dave Swift and Rhino have both been regular attendees in the past. I wonder whether they might be coaxed to give an insight into their playing or their careers. Also, I would love to head Neil Murray, as one of my early bass inspirations, talking about his life playing bass (from the National Youth Jazz Orchestra to touring the world's enormodromes, to working in the pit for We Will Rock You).
What about Lol Cottle? He plays a bit in the Surrey area, esp at Boaters in Kingston, but I'm not sure where he's based. Another player with a hugely interesting CV.
On techniques and the like, Dave Marks (Bass Guitar columnist, bass teacher, session player, rock and jazz sidesman etc), lives in the London region. He is someone I do kinda know and could ask if he would be interested. Top player and absolutely hilarious to boot. Might be dependent on whether he has a paying gig or not.