The E-Brake on a 3100 is usually pretty easy to get parts for -- especially for 1953 second series and later. The E-Brake cables go from the clevis rod into the wheel backplates and hook into a contraption that engages the brake shoes when you pull the lever (or push the pedal -- whichever one you have).
Is the wiper motor Vacuum? Those are pretty bulletproof. Rebuild kits are available from the various vendors, as are cab corners and entire fenders.
Here are some places to start:
American Classic Jim Carter\'s Chevy Duty
