there is no rubber core. it is a stainless steel solid prop. when i turn the prop with motor in gear i can feel the pistons moving.
It has either a rubber insert or a shear pin (old). Borrow a prop if you don't have one and give it a try, before spend money on other repairs
mine is a solid hub not a two piece. if i had spun the hub would it still push the boat at 10mph?