SEATBELTS!! Staying safe is the name of the game...

Okay. So I got out in the garage today to install my retractable seatbelts! Yay me. Take some befores, 'cause I like pics of my bus, and I likes my camera.

New stuff going in.....

Old stuff unbolted....

Annnnnnnnnnnnnd realize I cant find my damn "L" brackets to mount these vertically! I mean no where can I find them. NOWHERE. Pissed. So, searching around, I found these. Thoughts?

http://www.gotbelts.com/mounting-hardware-misc/m.products/84/view/4


Anyone know what size bolt that is that holds the seatbelt in? Trying to see if these will work. I HATE to start a project and not have everything I need.