The photo really helps lefty. Not what I imagined at all.
I agree that, as Thomas says, since this chair is essentially composed of pretty simple individual pieces with very little complex joinery, molding the entire chair would be counter-intuitive and not very efficient.
Better to compile the dims, etc. of all the individual pieces (this will be pretty simple, since most elements are straight), fabricate each piece and then assemble the mock-up. The mock-up pieces can then serve as the mother pieces for the casting mold (again, all individual pieces). It looks quite doable.
I'm not familiar with Ontario, but wouldn't another possibility be that the wood is birch, cedar or spruce, probably steamed originally?Info like this
might help you, as the construction technology would appear to be quite similar.