<<My set has 2 with brackets spot welded and 2 with the brackets screwed on. Was this the norm or was there a specific position for each shield. There are no other markings except L R on each one and the 69 AIM is unclear, at least to me.>>
The shields and supports are screwed together on the driver's side, and spot-welded together on the passenger side. See the Assembly Manual, UPC 6, sheet B9, View "C" and "D".