wiring connections for rear power window regulators.

Hi, have rear power window regs and door trims here, going for a "Get it going" setup where the only control is on the rear doors (like my current front window switch setup and wiring, plus cbf running too many wires for the time being).

door trims and window regs are from an EB ghia...

Basically from what I can tell there is 12v to one pin (from ef/l power window conversion) - top left pin from behind, then up and down wires (too middle ones).

but I also assume there is ground there somewhere - does it take this from either of the wires which run to the console normally (ie do I just ground both of these?) or can the bottom right (n/c) connection be grounded to facilitate this.