If this is a "restoration" and part numbers/casting numbers is an important factor, I believe the Bendix Master Cylinder Casting #2225621 would be the correct one to use.

If the OEM correct unit is not a priority then pretty much any of the replacement units will work fine. RockAuto shows a CARDONE Part # 101475 as a replacement for '67 Coronet and Satellite with disk/drum brakes but there are dozens of places including some vendors here where you can find a disk/drum MC. Its not rocket science, just do a little research and pick the one that works for you.