Advice on Mounting my Should Harness for SPF #205

[frankym]

I just learned that my car doesn't have the pre drilled holes in the rear frame rail that would normally receive the bolt for the harness. I also don't have the slit in the rear bulkhead for the single strap. I don't think i have any issue with properly positioning the slit, and using a spiral bit to cut out the space. However, I can't get a drill into the wheel well to put large hole squarely through the square tube up there. I purchased some mounting tabs that look like a flat rectangle about 2.5 inches long, and, I plan to bend the tabs to form a 90 degree angle, mount them flush with the frame upper rail, and use my mig welder to zap a bead. I plan to create a tunnel of aluminum foil in that space so that the heat doesn't torch the fiberglass. I would also weld slowly, to keep the heat down. Am i insane to try doing this?

I know I can purchase the rollbar mounted cross member, but then i have no shoulder harness for the passenger. Thought about it, and i want to mount through the bulkhead with the "Y" single belt, and loop through frame. I wonder if there is a way to get the nylon harness to simply wrap around that square tube and not bolt it at all through the frame rail.

Curious to learn what the earlier spf car owners have done.