Thanks J_J,
I just talked with the dealer again about a replacement valve. This valve is no longer available. He also explained about the leaking spools being caused by scoring on the spool or housing not by seals/O-rings.
According to the info I have the system is 2125psi and 20gpm so I don't think the valves you listed have sufficient flow. The dealer said they have replacing these with a Cross joystick around $400-$450 from them.
In light of all this info, I will just use the valve as is until I muster enough time/money to go for the replacement. Who knows, there may be something else go wrong that turns the whole tractor into scrap.
I still plan to attach the PB fittings and build my auger and
grapple. I will be able to use those on any other tractor as well. Nothing lost so far except a couple dollars worth of O-rings which I still have for other use.