The parking brake problem is simple- - - - -adjust the brakes. There's just enough contact between the shoes and the drums to make the Bendix self-applying function work in the forward direction, but not in reverse because the shoes are installed correctly with the shorter lining in the front. You're running out of cable length before the shoes get firmly in contact with the drum because the shoes are out of adjustment.

Bite the bullet and do a proper brake job- - - -the rest of us who have to share the road with that deathtrap will be grateful!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!