EYUP andt like ssmn sez you will be doing it again shortly mate im afraid;;;look at it this way the cylinders are leaking! ok the walls + seals are worn,renewed seals ,champion all working but you have only solved half the problem it wont last? now then when it leaks again ,and it will, it ruins the brake shoes ,more expense.now cast cylinders do resist wear but they rust damn,alloy cylinders dont rust but wear quickly ,you cant bloody win can you!!but if you shop at the right place cylinders are cheap so dont muck @ replace em,fit em with copperslip ect,make sure they are greased so they wont sieze up,you could also consider using silicone brake fluid because it non hydroscopic i found it very good on my vintage cars(layed up for the winter they didnt sieze up ).
cylinders are cheap if you shop around .hope this helps...dave