Brake combo/metering valve.

[Boydsdodge]

Hello, I am in need of a Combination Metering valve for my Imperial. Part number is 3583635. I need a NOS or Dealer stock.
I think I found my problem, being cast iron and not brass like easier valves will corrode easily when sitting for years.
Thanks.

 

[Boydsdodge]

Can these combo valves be repaired/rebuilt?
open clean out, reassemble?