maybe keep this link for the assembly manual handy. good info on how it was made originally.
on my original frame I had planned on using a foot operated park brake unit from a chevy s10. it would cover up the footwell vent though. the cable would exit the floor/firewall below the unit. the connecting parts between there and the rear would be easy enough to fab with your skills.
https://www.trifive.com/55-59Assy.pdf