The International Cessna^® 170 Association

The flap pulley brackets (p/n 0512149-1 and -2) were missing when I bought my project. Does anybody know if these brackets are attached at the top with a screw, bolt, or rivet? The IPC (17-4) only shows the bracket so I assumed it was attached just with rivets but now I see that other pulley brackets on the airframe use screws.

AN3 bolt and -4 rivet. Here's an overhead view of the RH side, facing forward and down.

Thanks Dave!