The question matters because Head had purchased the Chris Hoerhle patent on the continuous bonded edge, and was defending it aggressively. Thus a factory like Kneissl that refused to pay a royalty to Head had to use screws to hold on the edges, even if they were covered by the base plastic. Some 30 years ago I asked Joe Fischer about the Alu Steel. He had no access to the flexible contact cement used by Head to glue the steel to the aluminum. Instead he put rubber strips -- neoprene -- above the steel as shear layers, He believes he was the first to do this. So the answer, I believe, was no screws in the Alu Steel, and I don't know if Fischer paid royalties to Head.
Concerning the Kastle of 1964, I wrote an article about it for Skiing Heritage, because it was the last great wooden race ski and was used by all three medalists in slalom at the Innsbruck Olympics that year. The ski was of laminated ash top and bottom with a light core of okoume, and a decorative red plastic top skin -- but no fiberglass. Read the article here: