Closing out this thread - I was able to to use the template above - printed 1:1 and glued to the spinner bulkhead - along with a Dremel tool and carbide carving bit - to manually enlarge the holes and make them just slotted enough to rotate the bulkhead into the right position. I think I was lucky, and it was only because I needed minimal rotation that I was able to do that by hand. If the slot needed to be much longer, I would've been more leery of cutting it by hand. Conversely, if it had been quite a bit more rotation, I would've drilled new holes, and just left the old ones in place. I'll probably order a replacement bulkhead, as they aren't very expensive, and replace it at my next condition inspection, but honestly that's likely just my OCD, and this one would be fine long-term.
Measure twice cut once - I caught myself about to make a mistake - the slot needs to go in the OPPOSITE direction from where you need the spinner screws to line up. i.e. in this picture, the arrow points from the existing spinner screw location to the required screw location (clockwise) so the slots needed to go opposite that (counterclockwise).
I actually "overdid" this a bit, I needed 3 degrees of rotation, but cut a slot to support 5 degrees.
Finally, be careful when you get your prop back from overhaul, and be sure to check the static stops. Mine took 4 1/2 rotations - or about 900 RPM - adjustment of the pitch change bolt to bring the static RPM down to 2650, and the first time I tested it, the RPM went up
very quickly - fortunately caught it before any true overspeed condition.
