Get the right connection and splice it into the wiring harness?
Did you get the master cylinder from a junk yard?
If you can find a junkyard, I'd expect that connector to be cheap.

I've got no idea.
Before you do anything, you should bleed it and get pressure on the pads.
Prove it works.
The wires just light the brake light.
You can put your foot on the pedal and do that till you get it right.