I used a foot brake from a 90's GM pickup. released with the original 1952 release rod cut down.
To get the cable to exit where I wanted it I had to rotate the assembly and to get full travel on the pedal I had to shorten it and cut a pie wedge to rotate it. So it has lost some leverage and you have to push a bit firmer but it works fine.
Here is a shot of it mocked up on the inner cowl panel before that got welded in.