You can swap the brake pedal on the early clutch pedals to make it work, if you really wanted to. The early brake goes around the column to the right, the later ones to the left, but the clutch pedal and bracket are the same (minus any braces from the 340 cars).
Buddy of mine bought a Duster that had been converted to a 4 speed, and always thought the brake was funny and kind of hung up when coming back up off the floor. When he tore it down later, he found out whomever did the conversion used the early pedals and beat the column jacket in on the right side to get it to work (for the most part).
If you find the right auto brake pedal, you can even chop the pad down and make your own later 4 speed brake pedal. That's how my friend fixed his problem. They aren't all the same, the ones with a 90 degree twist at the pad really don't work. Just look at a later 4 speed brake pedal and find one that looks the same but with a bigger pad.