+1 on them being installed
after the car was painted - Both for the stop (in the door jamb) and for the guides on the bottom of the door.
The ones at the bottom of the door are sort of special in that their heads were thin (not as tall) when compared to other bolts used on the door.
Each had a washer either steel or rubber. Not sure why there were two version just reporting that their were and it does not appear to be a production period thing at this point but would have to look at more examples to determine that for sure. Have more examples than what I'm posting
Thin counter sunk head zinc dichromate bolt and rubber washer
Thin counter sunk head bolt with steel washer