Yeah that's probably unturned. I keep backing plates around for 305/450, CB350, CB175, CB160 so I can turn the shoes without a customers backing plate being shipped to me.
It's going to depend on how easy they turn....some materials turn real easy...other compounds you have to be real careful...they will all of a sudden grab the cutting tool and self destruct. If these like to self destruct I'll probably have to get a small charge for turning them to cover the 1 out of 20 that self destruct.
Anyway...turning is really pretty quick and easy if everything goes well....so I'd only want about $10 to turn them.
Hopefully I'll be able to turn 200mm drums if I get the lathe I'm going to bid on.