Joseph,
You should not be using hub "timing" marks to actually set the timing. This should be done with a degree wheel and "buzz box" (in place of the feeler gauge) after finding TDC in the usual manner. The manual spells that out pretty clearly. The method of using gear teeth marks and reverse rotation is to get the mag close for distubitor block position, not timing. Once the mag is "roughed in" to assure the correct cylinder will fire, then the timing is set. Make sense? To break it down into simple steps lets try this:
(My method, little simpler to think of)
1-Set Magneto to #1 Firing position (mag not installed)
2-Find engine #1 TDC using the dial indicator method, and set your zero point on the degree wheel (timing disk)
3-Set the engine to the firing point (22 degrees BTDC for yours)
4-Install the magneto loosely without losing its position (roughing it in)
5-using a buzz box, rotate the magneto until the points just break open with the crank at 22 deg. BTDC.
6-secure the magneto, and recheck the timing, adjust if needed.
Simple as pie
Gotta love old engines.