I finally cleaned up some of the surface rust around the lip of the windshield opening. I used Naval Jelly and it seemed to work okay. I probably should have left it on a little bit longer but its already primed and painted flat black. Luckily the flat black matches the flat black already on the car. At least it looked that way last night in the garage with some dim lighting. I should be able to get the defect free windshield in by this weekend.