[DrBob]

These bikes did not sell well when they were new, but have a decent cult following today. You need to hook up with the various owner's clubs in various countries on the internet. Do a Google search for "waterbottle" and "Kettle Club of England", as the bike had different nicknames around the world. You probably will find a decent niche market for your barn full of parts, and will make some folks very, very happy. Spares are particularly hard to find in the UK, so you will probably get good response from there.
I stumbled on to an absolutely beautiful one last year, in near perfect mechanical and cosmetic condition, for $1000. I grabbed it and sold it a week later for $1600 after riding it a couple times. It was just as I remembered- that two-stroke exhaust note, and a nice smooth ride on the highway. I thought about keeping it, but I knew I'd rarely ride it, and a buddy had one I can have for free if I want another restoration project, so I went ahead and sold it.