mate, they are all as old as yours is. rebuild yours for around $30. pull it apart, take the rubber seal to your local brake parts shop (not malz or pedders, but like brake bonders or something) the seal is about $3, get a brake cylinder hone like this, from the same shop: http://www.ebay.com.au/itm/Small-Brake-Cylinder-Hone-3-leg-Honing-Engine-Tool-19mm-62mm-2756-/400280047926?pt=AU_Motorcycle_Parts_Accessories&hash=item5d328cd136
chuck the hone in a cordless drill, lubricate stones with brake fluid and hone till its all smooth inside, clean out sludge and reinstall new seal with rubber grease and reassemble. bleed and you done.
google it as well, there is a guy with a pantera that has a good guide. i have linked to it in either the miscellaneous tech section or the evo 1-3 part. search for slave rebuilds or cylinder hone or something like that