looking for shoulder belt attachment location
Thanks for the input guys!
I chose to fabricate anchors as per the photo below. The dimensions of the plate allow for insertion into the large hole and then 90 degree rotation.
Fabrication steps:
1) The hole drilled through the plate must be 1/2" to accommodate the non-threaded part of a seat belt anchor bolt.
2) The five fender washers are held in place with a 1/2" nut/bolt to centre them during welding to the plate. The washers bring the finished thickness up to the level of the sheet metal.
3) A seat belt anchor bolt is used to hold the nut in place. Use additional fender washers on the front side to ensure the nut is tightened securely.
Installation:
1) The anchor bolt must be removed to install the assembly through the hole and then rotate it 90 degrees.
2) Re-install the anchor bolt so that you can hold the assembly in place to tack it. Remove for full welding.
3) I used fiberglass bondo to provide a clean finish over the plate area.