Ernie, wondering where you ordered the backplate.
Horizon and Advantage Hobby both have the alum backplate in stock I think. A friend gave this one to me - think he got it from Horizon. Just a standard Saito 82 part now. It sure is a good feeling to get rid of the plastic one and reassemble it with the solid aluminum backplate. You'll need a couple of new metric bolts to mount the carb though.