I also strengthen the pedal box a lot:
The metal the throttle pedal sits resembles tinfoil. The clutch pedal assembly just didn't work, so I installed a willwood master cylinder and the cage for the master cylinder taking the stresses away from the pedal box:
See the smaller nuts inside the ground cable loop and towards the front - thats where the cage is bolted to. There is a thicker plate on the top to re-enforce the area.
You can see the clutch master installation here:
I'm considering options to change the whole thing to a properly design and tested pedal box system, but not had enough time to look into it recently.