71 (?) cheyenne brake master cylinder in '64...keep or change?

[GMC Jester]

So when I got my 64, there was, too my best assessment a 71 (?) cheyenne brake master cylinder. I am assuming the booster is a matching booster, and in better condition than the booster.
I was planning on treating the boosters' rust, and but just replacing the bmc.

My question is this: Is this advisable? I have 4 way drums and do not want to go back to the original single. I've done all the reasearch I can, here and google, but not sure if there is something differnt or better I should put in its place.

Follow up: Fenco bmc from autozone? Napa? bang/bucks...