Using a piece of 1/16" aluminum, four shoulder harness bolt attachment plates (3/4" width) were cut out after drilling the holes for the shoulder harness support bolts and the nutplates.
The alumium pieces were cleaned with Alumiprep. Four shoulder harness attachments were also cleaned. These four harness attachments were removed from a 1969 Citabria 7ECA (G-FAKI) a few years ago.
The shoulder harness bolt attachment plates were then anodized and rinsed off.