remote battery shut off switch

where have you guys installed this where the pull handle comes out the rear? 1973 dart swinger.. master battery is on left side, slave battery on right. I all ready had one in a box in let rear. adding remote rod set up. was getting creative with a bell crank that has a rod in out between left bumper guard and the center peak. that way cold still be a push /pull. but where do you get the swivel bracket that goes on the switch, tat takes place of the flip lever at? can only find this with a kit from race shop. this has to be a hardware item right? slips over with set screw, and has a ball /pivot swivel on end. or I can get one of these, any suggestions..... need this set up to work with the switch location all ready.