Found my original 74 bracket. It was rusty cosmoline, so cleaned it up and painted it. The studs on the 70 version did not want to come out easily, so left them alone. So swapped the parts over to the 74. Had to enlarge the hole for overcenter spring pin, otherwise everything went together smoothly.
Looks like the 70 pedal bracket is for manual brakes, the studs with nuts show up just above brake master cylinder on members restorations pics.
I'll put it up for sale, maybe someone needs one or are they real common???