Don't know much (read 'anything') about sidecars but did fit one about 20 years ago to a Heavyweight AMC steed - and promptly parked it in a 6 ft ditch full of water after about 20 minutes. I reckon most thieves would have done better! The water was bad for all concerned - the nettles all along the banks were worse. Wifelet of the day unimpressed as driving into the ditch was only the culmination of a somewhat erratic progress that scared the living bejasus out of both of us. A relief to crash really. Obviously didn't follow or have access to great info like what's here when I 'set it up' ho ho.
Having said that, I still have the chassis (the D/A body crumpled to dust and the remains were waterlogged in no time). It's a Watsonian Mk 2 (I think) with a steel stud-mounted wheel about the diameter of a Mini's. It's straight, it's all there including the grab rail with lights (bar some of the mountings), and if anyone from this forum wants it for nothing it's sitting in Normandy and I'd be pleased to give it a good home. Send me a private note if you're interested, ever likely to pass through northern France, and I'll stick your name on it and hold it for you as long as you like! Groily