RE: CMP BF109F BUILDING THREAD
Hi Lou
My alum backplate is 5.695" (144.73mm) at the point were it meets the fuse and tapers to fit the spinner without step up or down. As in the factory one, just alum. Its around 4mm thick.
Your really better off unpacking the spinner and giving it to them. I had to test fit my cut a 100 times. But im not a machinist at all.
Steve