Presumably the Goat hair cover was waterproof as I suppose were the dyed Ram skin covers. The Lebanon Ceder would have be a hardwood to avoid rotting, insect infestation and damage. The whole shebang would have had to been light enough to carry without too much of a problem. The gold and brass would not rust and there are no steel and iron items which could make a simple electric cell which would lead to rusting and staining. Everything makes sense. Really enjoy and learn thank God and thank you Rabbi for passing the message on.