Brake part for 61'

There is a bolt that threads into the back of the master cylinder that holds the outlet fitting against the master, also the stoplight switch threads into the bolt head. Where could I find that bolt more readily from other ford models i.e. online,local parts store or catalogs? My bolt head is just to corroded to fit a wrench on to torque properly.

Thanks, spydycarnge
GC, Michigan

Yes, this bolt is similar with the exception of the hole that runs through the bolt and comes out the bolt head, which is threaded and the stop light switch is than screwed into the bolt head.