VacMadMan
Jim,
Thank you! I never knew that the toe-touch control and rear axle shaft on models 508 and back had the smaller holes for the #8 screws. This bit of trivia really makes me want to find a 1948 or older Kirby service manual!
Kirby did the same thing with the front axle clamp screws when the 516 was replaced by the 517, by using larger screws to hold them in -- in this case, the holes at the bottom of the fan case for these two clamp screws were now #8 size instead of #6.
~Ben