Duster people !

I can't get a pic for you right now, but they are rubber bumpers about the diameter of your thumbnail. They have a skinny "tail" protruding out the back that pokes through that hole in your deck lid and pops into place.
You can get them at Hardens Muscle Car World for about $2.00 each. Ask them about part number CH2002, if your car is 70-74 Duster.

Jerry