...and of course, I was once again blessed with a bunch of real troupers! After exchanging worried emails until lunchtime, we decided to go ahead, and out motley crew assembled at 4.30pm. At this point, my husband had spent nearly six hours in the studio, building the rigging and the ledge. The studio, by the way, was flooded, but that's another story!
To cut a long story short: all is well. We got very wet and very cold, but everything functions the way it is supposed to, provided we take things slowly on the day. Which we will do.