I believe the pedal mount is the same as '40; it uses 4 5/16 bolts IIRC the top rear is thresded into the bracket through the frame and the other 3 are bolts and nuts. There must be some difference as the '40 is marked O1A. I think the same bracket is used through '48. There is a snap ring on either end of the cultch/brake shaft and it's probably easier to remove the pedal arms before removing the bracket. The pedal shaft is pressed in the bracket, but is replaceable.
39 does not use an equalizer shaft. The mount is very different between 39 and 40. I much prefer the 40 up style as they do not require the steady rods. I put a side shift trans in my 32 and used the later clutch set up. I had to make a special offset pedal mount but it all went in with no frame mods. I did work over the pedals The 40-48 stuff is way cheaper and more available. Someone gave me my pedals!