One of my current areas is modifying the '53 cab for a foot actuated parking brake, as it previously had a hand lever acuated one. A big "thanks" to Dads50 for his description of how the bracket attaches to the firewall in the thread "Inner Fender Woes". Both his description and pics really cleared up the situation for me.
http://s837.photobucket.com/user/daveydouglas/media/pb3.jpg.html