I got a pedal bracket that was said to be for Mav/Comet but it looks a little different than the one I put in my car.
I would say that is NOT a Maverick pedal support. Never seen one with the round firewall pass thru tube.
if its not out of a mav/comet id really like to know what its out of. if the tube part was cut off it would be hard to tell the difference. the unpainted one is out of my 73 mav.
You can take Maverick clutch pedals and they will slide right into a non-clutch pedal mounting. It has to be an early Maverick pedal mount, as the later ones were different in how the brake pedal mounted in the bracket. I am not sure when the year changed. So in other words.....you can take those clutch pedals and mount all the necessary parts (clutch pedal return spring, etc) right into your 1973 mount you have pictured above.
That's exactly what I did with my 69.5 - I stripped another early Maverick in a junkyard of it's standard shift pedals and related accessories, removed my automatic brake pedal and the junkyard clutch/brake pedal parts went right into the same frame.