[Eliot Ness]

Yes, wirewound resistors can be very accurate, especially at lower ohms, plus they have the ability to dissipate more heat.  They also do not drift like carbon resistors so they usually measure good or open.  If your wirewounds measure OK and look good cosmetically (not falling apart) I would leave them in.

As far as replacements go I would stay with wirewounds for their accuracy and heat dissipation.  Without seeing the schematic or the resistors I couldn't say what wattage they should be.  If one is marked 10W then you could probably make an intelligent guess by comparing the size of the others to the one marked 10W.