The part is plastic, there are four of them. Ineed the right one as you face the window outside.
A home owner from Hickory, NC says:
October 28, 2015
I fliped the left one to show what the right one would look like. The part is 1 3/4" x 1" x 1/4". As you roll the window in it catches the post in the picture to pull the window tight aganist the frame. Hope you can help me, the house was build in the 60's, so I guess there that old. Thanks for your help.
Paul from SWISCO responded:
October 29, 2015
We have two possible replacement awning vent hooks that come to mind. Take a look at our 36-009 or 39-010. Please compare them to your hardware now and see if either can work for you.