Porportioning valve questions?? Need HELP!

I am going to put sbp Kelsey Hayes brakes on the car.

I have an original KH porporting valve that hasn't been used in 20 years and has been on the system until a month ago.

I have a porporting valve that is still on a 1975 Swinger that has lbp brakes on it.

Is there a way to clean up the original valve?
Could I use the Swinger valve?
Would I be better off with an aftermarket valve.

My goal is to put the car back to what it originally could have came with but with brakes I will do what ever is best.