Gerry is one of my feelers. if he or restoration specialties doesn't have them, i'll be trying HH idea.
found this on ebay for the 1" tall beltline clips, but I still like the idea of sealing from the inside with rubber washer nut combo, since I have to put sealer on the wire clips (rtv) and it may not be as good as the rubber washer that I can tighten down.