Oddly enough, the female ends of an old serial computer cable are the same size (or close to it) to be used as a cartridge clip. That is what I used. Care must be taken to dismantle the connector, but eventually you will have the necessary clips. While you are ripping the cable apart, you will find the color coded wires that you need. all being basic white, but you will find one with a red strip, a blue strip, a green strip and so on. I would also find some heat shrink tubing that would just fit over the clips, to help them keep their shape and they do help keep the clips on the cartridge pins.
Take care soldering the old Empire pins. The better cleaned they are, the better they will solder. You may need a volt/ohm meter to trace the wires to the various RCA pins and shields to determine correct color coding and wiring.
Wayner