Crankcase 6.8 quarts with filter I use 15W40 Rotella or Chevron Delo 15W40 depending on what is on sale.
Trans./hyd. with 4wd 36 quarts
without 4wd 27 quarts Both are JD hy guard made by Troco (sp?)
4wd housing 9quarts 80/90W gear oil
Specs are from my JD 1050 manual. HTH
Any carquest/napa/Oreily's that has a paper catalog with someone that can use it (gasp!) should be able to get filters for him. They all have Wix part#s
He will need the tractor serial number as there are two different trans/hyd filters depending on year.
There are two air filters as well, inner and outer. The inner gets changed every other outer change.
Buying all the filters and enough oil for the engine change is about $80 or thereabouts.