By 1963 the shells were 5 ply Maple/poplar/maple /poplar/ maple,my 1966/1967 kit has 5 ply reinforcement rings,I have heard some kits from that era have solid Maple re rings.
Cleveland and Dayton era drums are definitely stout,look how well yours have held up after 40 plus years, the drums got lighter after that,lugs got lighter and mounts went from being machined to cast.