Witch Master cylinder? HELP!

FABO,

So bought a "project" 1965 Barracuda from a fellow who was switching be brakes from drum to disc, on the front...

Well he has the rotors, proportioning valve, wheel cylinders and all, but no Master Cylinder. So I need a Duel Master Cylinder which they didn't have for a 1965...

My concern is that maybe that the proportioning valve works best with a 'particular' duel Master Cylinder. Can anyone tell me which one goes best with a # 39410 proportioning valve? And maybe where a guy could get one of them?

Let me know if there is any additional information like the disc brake wheel cylinder # (it's 71312) or something.

Thanks.

65Cudafix