HFR, thank you for taking the time to chase this trivia.
It's not even a small deal but as long as I was ordering fasteners I thought I'd try to ID the correct ones.
The pan-head screws you show may be right but I still haven't found a document with the part number. The lens doesn't have an obvious tapered seat, so I'm leaning toward a flat clamping face on the screw. The seating face in the lens could take a larger diameter screw head but I had nothing like that in my pile.
I ended up finding two of these which are close to yours (#8 x 1-5/8 pan head), just shorter (#8 x 1-1/4 pan head):
They protrude plenty far enough to engage the clip:
Yours are almost identical to those used on the rear taillamp lenses, but are bright stainless while the taillamp lens screws are blackened stainless. They would also work fine. This one is off my taillamp lens and is carried by AMK:
AMK sells something the same size I used (1-1/4) in either bright or blackened SS:
https://www.amkproducts.com/bulk-fas...oduct_ID=11453
https://www.amkproducts.com/bulk-fas...oduct_ID=15069
Mike