Cheers. My back brake is still out, cable snapped by the lever. What should be a straightforward replacement is made difficult because I will probably have to remove a lot of the bodywork to get to it. I take apart and fix washing machines for fun, but I don't have to go 15-25mph down the road on one!
I'll see if my local bike shop can do a service on it, and if not then I'll try myself.