That should be like my '39 and the blade is rivoted to the hub and is replaced as a unit. I need one also, as a previous owner tried to put a too long fan belt on the engine and cliped the blades to make it fit.
I think he is talking about the front pulley for the generator, not the fan itself. Or at least that is what I get out of his post. I didn't think the screw on pulley came out till 40, or maybe 39 on the Deluxe.