3 point seat belts?

Hmm, 7/16" is the size that came with them. I don't have any of the original hardware, which is why I asked.

The included bolts seemed like kind of a tight fit, and I didn't want to strip anything by forcing them. Guess I'll go grab a pack of shorter 7/16" bolts (the included ones are too long for the shoulder mount anyway) and see if I can make it work.