Good thing I never throw old belts away when I dismantle a car. I found a good set in the attic. These belts are a bit more modern than the car, but I don't mind.
These were the only holes I needed to re-drill Each belt needs three bolts, but I could only find two holes. I realized that the holes in the floor, near the sill were covered when the floor/sills were welded. They were visible from underneath the car. I only needed to drill one panel to access the hole.