Hi Lance,
the photos seem to show that the '72s forks don't have a notch to locate the speedo drive, it's clamped by the axle instead?
What the book sez about positioning the clamp-up fork leg on the axle is to bolt the threaded side up tight, slacken off the clamp nuts and vigorously pump the forks up and down with the front brake hard on. Wherever the fork leg positions itself after that is where it wants to be so do the clamp nuts up.
Book also sez to tighten the front nut first to fully close the gap then tighten up the rear nut.