The Mike Lucas site has a very useful and interesting forum for maintenance and general advice. I've had a 29 for 5 years and learnt a huge amount from this website.
There is indeed also a formal 'owners club', it's called the Sadler & Starlight Owners Association, and has a website at www.sadlerand starlight.co.uk. Produces an interesting newsletter and organises several events each year (mostly south coast though).
Hope this helps.