After reading the May 2013 article in Comanche Flyer on Prop spinners, I checked my installation, and sure enough, it was installed incorrectly, in that, the holes on the spinner and bulkhead line up (which they shouldn't). But alas, there never were any spacers under the jam nuts.
In checking the Parts Manual, there is no reference to the spacers. Does anyone know where such 15/16" SS spacers can be found, what their specs are (OD and thickness), or what the Hartzell/Piper part number is?