I'm sure I read somewhere that C&C replaced the wooden mast step with a metal (aluminium?) on the 30's to prevent rotting when it got wet.
I looked at one recently, a 1976 vintage, and it looked like this:
Is this one a "rotter"? Looks awfully like a large lump of wood there, as well as a big lump of aluminium. I can't remember if the wood actually felt soft where it is discoloured.