Yikes..... I should remove my plywood washer from my pattern plane with a Saito 150. It only has 25+ gallons of fuel ran thru it I would hate for it to start slipping and fly apart now.

While the aluminum spinners are the best route and the only spinners that I will use on my planes, a three bade aluminum spinner that size would most likly have to be custom cut. Switching to a two blade will still be in the $30 range to get going. A 1" square piece of aircraft ply sanded and drilled to a good fit will cost almost nothing.
Dowayne