I may be totally confused by now, but it seems the first photo from thrashing cows shows the correct setups, which doesn't seem to match the text from tdenkler (because tdenkler doesn't acknowledge the difference in arm lengths between manual and power brakes) and the drawing from commando1 doesn't seem to match either the text from tdenkler or the photo/identification of arms from thrashing cows. In any case, I believe the pivot point of the clutch arm is the same as the manual brake arm pivot point and the power brake arm pivot point would be higher (as shown in thrashingcows photo). tdenkler I believe is only saying the power brake pedal is 2" lower than the manual brake pedal as installed in the car (or in other words, the power brake pedal is 2" closer to the floor than the manual brake pedal) which is correct.
In evaluating the pedals and bracket assembly that I originally posted for sale, I took a look at a 69 Polara bracket assembly and it is identical to the bracket assembly of the pedals I have, so I am concluding that the setup I originally listed is for a 69-73 C body manual transmission-equipped car with manual brakes, rather than 1965 - 68. The B body brackets are certainly not anything like the bracket assembly I have. So I think I now understand what is going on, but then it may well be that someone messes me all up again! Thanks for all the input guys.