Spinner concentricity

So we're fitting a constant speed prop to the RV-9A, and when we put the spinner backplate onto the back of the prop, it appeared off-center. Attempting various measurements indicates that, relative to the four holes where the backplate mounts to the prop, the part is out of concentric by maybe .050" to .100".

Anybody seen this before? I called Van's this morning, and there is no spec for how concentric all the parts need to be.

Thanks!

Ed