, unfortunately no plans available... as you can see, different hoisting systems were engineered and custom built by professional companies around here. AFAIK, most components such as motors, pulleys, chains, cograils, etc, are available in the industry.
A simpler cheapie solution could be designed using 3 electrical hoists... assuming the rafters or whatever roof is strong enough. We have a couple of those plastic canard toys (aka Ez
) on the field hanging on a single elec hoist, backed-up by a relief cable once up.
Re insurance requirement, all aircraft on hangers need TP cover... though the only event I know of, happened when an aircraft lift, for reasons unknown to me, tipped and dropped its load with dire consequences