Expect to find a lot of side-to-side play with the clutch and brake pedals, but this can be easily rectified.  Underneath the left frame rail is the shaft on which the pedals pivot.  The shaft is hollow, with provisions for a cotter pin at the very end.  To use this repair, the pedals wouldn't need to be removed as shown:

Here is the stock arrangement.  A bracket that runs from the master cylinder fits on the end of the shaft.  A cotter pin retains the bracket and pedals, but no side pressure is applied.  The pedals can wobble quite a bit on the shaft even without any excessive wear.  At the far end of the pedal arms, the foot pads could rock side to side almost two inches on my wagon:

At some point, Willys devised a retrofit kit to take up the slop.  By pressing the bracket against the pedals, free play is minimized.  A threaded stud will stick out from the hollow shaft.  A solid pin takes the place of the cotter pin and holds the stud in place.  A hollow cap slips over the end of the shaft and has a threaded hole so it can be tightened on the stud.  This applies pressure against the bracket.  A jam nut prevents the cap from unthreading:

 

This close-up shows the stud installed.  Only the cotter pin needed to be removed, with the bracket and pedals staying in place.  The solid pin has been slipped in place to hold the stud.  The pin's length is the same as the shaft's outer diameter. There's nothing to stop the pin from falling out at this step of the installation:

That pin was only a slip fit, but is trapped in place when the cap is installed over the end of the shaft.  By turning the cap, it threads down onto the stationary stud and the bracket is pressed against the pedals.  Don't overtighten, and doublecheck that the pedals are still free to operate without binding.  Little more than hand tight was needed, and the jam nut locks the cap into position.  The play at the foot pads is now less than a quarter of an inch.  If you look closely, you can see that a common plumbing item was the raw material for the cap in my version:

My inspiration was watching somebody pay a small fortune on eBay for a NOS Willys repair kit.  Since the shaft is hollow, an even simpler version could be made with a long bolt extending all the way through.  Use a very short piece of pipe as a spacer around the end of the shaft.  A thick washer large enough to capture the spacer will squeeze everything together as the nut is tightened on the bolt.