If you can suck air through it from the hose side and not easily blow air into the hose side then it is still good.
Personally I am going with an offenhauser aluminum valve cover when mine goes back together. Adding baffles for PCV and a small threaded port that will allow me to use a PCV valve from modern japanese engine. They use small thread in units with full metal internals that will last forever with cleaning. The offy unit also has the advantage of a rigid gasket surface.
