Thanks guys.
My existing control valve is Gresen it is for my John Deere 36A FEL on my 1965 JD 2010. I have been trying to find a rebuild kit but have not had any luck. It is a Gresen 2712 and I have not been able to find any reference to it on the Gresen site or in a intense search on the Internet. I have not rebuilt a control valve before but am assuming that it involves o-rings and some honing. Also no luck finding information in this area on the Internet. Of course dummy me, I could call the JD dealer, duh! Always my last thought because of so many discontinued parts.
Farwell