I've looked at all of the above. I've even priced out welding them in 3 pieces, but the stainless welding and grinding and polishing was very expensive. Drilling for dowels was expensive. Laser cutting of 1" metal required such high power and so many passes that the price was out of sight.
Plastic blades don't weigh enough.
At Kodak, they were either stainless or teflon coated low grade steel or iron.