Did you find the repair kit on Amazon. I had no luck.
I actually could not find the Anderson Valve kit on Amazon either. Anderson Brass referred me to Fitzilla.com. The kit can be purchased there for $35 plus shipping. The folks at Anderson Brass, after hearing what I was experiencing, didn't think that the valve was causing our water pump to fail to build pressure. Like Jim Belletti, they thought it was more likely a problem with the pump (check valve, diaphram, etc.). However, I took the cartridge out of the valve body to see if any O-rings were damaged and did not find any that appeared damaged. I lubed and reinstalled the cartridge and connected our trailer to city water to check for leaks. No leaks, so decided to check pump one more time. I disconnected from city water and ran pump with valve in the normal position, and to my surprise pump built pressure and system operated as designed. I have no idea what fixed it or if system will continue to operate properly.
Thanks again to Jim and Anderson Brass for their help.