Stupid question, but are your line cords 2 pair?
Your wiring is correct, 12 phones per card so only the last pair violet/slate are for external page.
You can measure voltage on the jack . It's been so long but you I think you should see voltage from a white/blue or blue/white wire to a white/orange orange/white wire at the jack. I think around 24-28 vdc should be there.