K1 Triple valves

Out here on the Sumpter Valley, we are in need of info and help on K1 triple valves. Is there someone or a company that does professional rebuilding of the K1's? Are there any parts sources for K1 parts including gaskets and packings for the brake cylinders. We've pretty much concluded that the internal parts of some of ours are worn to a point that they need replacement or more attention than we can give in house. Does anyone have spare k1's that are rebuilt or rebuildable for sale? Our carman has been using graphite in the triple valves as per rebuild instructions from the early part of the 20th cent. We have also tried using ATF as a light lubricant during reassembly. The ATF has the downside of collecting small particles of yuck after a period of time which is undesirable. Any thoughts on what current practice is on those RR's still using K1's? Any discussion here would be appreciated or backchannel me if you like. Thanks!