Toyota remote mount reservoirs use a 16mm or 5/8 soft hose which is resistant to hydraulic oil, it was available very easily in Karachi rubber market near saeed manzil and also at plaza. Same for the 10mm return hose. The only difference being that it will be straight rather than moulded like original. You can make a sharp bent hose with some brass elbows
Original parts are usually not available for such items for old cars in Pakistan as customers dont have two coins to rub together.
Btw
You mention that the spool valve housing is sloppy, that small bushing can be replaced by a precision machinist.
And I hope you are using the correct oil which is regular ATF in it. Toyotas leak with other oils except atf or iso32 aw hydraulic.
Check with about 5 psi air pressure on the oil tank to see where the suction hose is leaking from, similarly check with a vacuum system to see if the system is not pulling air from the return line connections (this is a very annoying leak as it manifests as a whining pump and can cause jerky steering too).
Ive rebuilt lots and lots of seiko-kogyo steering racks. They are pretty decent quality. For original “toyoda” brand stamped pumps you can cannibalise the cam ring, rotor and vanes from another pump (they interchange in a lot of pumps). The bad part is the pressure relief valve, if its bad, you need a different one.
