Bought a cheap drott 40 with seized engine and rebuilt. Detroit 4-71. On to the hydraulics. The low pressure return fitting at bottom of hydraulic swivel broke off. Tried to weld on machine but discovered it’s cast. Does the bottom casting of the swivel come off separately or do I have to pull the whole hydraulic swivel out of turntable? Any idea where I can find one from a boneyard if can’t get it welded up off machine? Thanks for any help. I have service manual but struggling to understand if that piece with the ports will come off from bottom because it says the hydraulic swivel comes out from the top. I don’t see how with that piece on it.