Usually, the item numbers shown by Ford on assembly drawings are also the item assembly order - usually. So, obviously item 7, both brackets to the outside edges of the radiator support, go on first. Here's the trick part, both headlight buckets, items 10 and 11 are installed to the fenders, then item 8, the stone guard with one each "screw and retainer" 379749-S2 installed on each end, and then that "sub-assembly" is dropped into the headlight bucket/outside brackets, item 7, and attached to item 7 with 2 each 376838-S2 nuts from underneath.
Try a "dry" fit with both item 7 brackets and both headlight buckets installed, then try the stone guard. The hood lock support (item 1), the center bracket (item 6) and the grille (item 5 - ?) should be in place as well.
It's been a while since I put together a 68 so I'm running on "memory".
The "screw and retainer" 379749-S2 is still carried by AMK. Use AMK stock number B-11564.
Jim