Dave - given the number of float change-overs done at our airport there's a chance that somebody has a gantry on wheels that could be used to lower the crate to the ground. Also I suspect there is a tracked skid-steer which may have forks available for it. I'm sure for the right inducement the appropriate equipment could be rounded up.

Oh, one more thought... two hangars down from you the owner has a large farm tractor with front-end loader and I'm reasonably certain he has forks for that loader.