I have one on the way this morning but was going to wait to announce until it was in my hand.On a hunch I went to Messicks parts and looked up the LA526. According to them the load check for that loader is $135. Part number is YS020-93100 and again according to them fits 35 other models including - you guessed it - the LA525.
Dan
Remembering from old motorcycle days, I know some dealers in a large network will likely have NOS of items no longer listed by the mfg. So I called Marshall's, my local dealer, yesterday and asked the parts mgr if that was correct for Kubota. He said yes then used a system Kubota dealers have to look up NOS for particular items at other dealers. He found about a dozen for this check valve, including 2 in NY.
Then in another neck of the woods and before I could order, my "expert" mobile mechanic let me know he had the valve being sent to me overnight. I should have it today and with no extra cost to me! My opinion of him went up a notch but, then again, his not understanding small tractor hydraulics (works mostly on large construction and earth moving eqpt) was the whole cause of my problems.
Regarding YS020-93100, I cannot understand why that was never offered as a substitute for YS368-93100, the item number for the LA 525! Every time I looked for YS368-93100, the response was always "Product has been replaced by YS031-00100" (quote from Messick's web site); this is the whole spool valve that Messick's sells for $1187.54. I do note that Messick's site calls YS020-93100 only as a "kit valve" whereas YS368-93100 is described as "kit valve, load check." A picture would help. FWIW, Kubota USA site says YS020-93100 "not available" even though Messick's has it. This may remain as one of the unsolved mysteries of the universe.
Overall there is one clear conclusion: you, with only minimal information from an amateur reporter, called it 100% right for both messes. Once again, Thanks Dan!