The bracket in your third picture attaches to the side of the trunk opening on the body. The hinge pin is screwed in from the inside (head facing towards the outside of trunk) and into the lower hole of the trunk lid in your first picture. The countersunk holes should be in the new bracket that you have as the screws should have flat heads. It will take several attempts to get the adjustments correct for the trunk lid to fit.
"It will take several attempts to get the adjustments correct for the trunk lid to fit."
There’s the understatement of the day!![]()