As it happens, I had to go to Ace this morning, so I took my factory side scoop screws to match up. Yes, it is just an oval head sheet metal screw, but there wasn't an exact match.
The shaft diameter of the factory screw is a little bigger than a #8 screw, but smaller than a #10. Same with the diameter of the head.
But in my opinion a #8x1-1/4" stainless oval head screw is the closest match and will work fine. It's just a hair longer than the factory screw, but that won't matter. And even though the head is slightly smaller, it seats just fine in the factory side scope holes and looks good.
Comparing the two screws: #8x1-1/4 on the left, factory screw on the right: