Case 530 w/ #31 hoe drifts

Hello,
My old 530 (not CK) hoe has a one piece control valve. I could say the old girl works like new except boom drifts down & swing can drift. I"m 99% sure the by-passing is actual wear in the spools & casting. Its useable but not right. I"ve watched for years for a NOS control valve. I"ll guess a stackable control valve would be easier to find. When I think about converting to some other valve: Secondary relief setting for all the different cylinders. It makes my brain hurt. I"ve had a "want it now" listing in ebay forever. Reads like this: I"ve restored a 1961 Case 530 Loader & hoe. Hoe model#31. The hoe drifts down. I"d like to find a new old stock control valve. The numbers I have are D26885, D25852, D25856. This is a one piece casting. If you have any new control valves for Case let me know, possibly I can update my machine. Thanks, Big-Hoov. Ideas? Best wishes & God Bless America, Dennis.....