It doesn't matter whether its out for an hour what matters is that professional flight crew can operate the aircraft in the environment that they are presented with. Having an ILS on 34 in Melbourne (and that would also have to include 05 AD 11DN 30HB 14R LT) might make it easier but it won't make it safer if the person at the controls does not have a good knowledge of how his/her aircraft works. I flew an approach into Sydney yesterday that gave me all the appearances of an ILS with an LDEV and a VDEV indication and FD's that were centered. I would have been in for a nasty shock however if I thought that it was going to autoland as well.
Modern FMC's, autopilots and glass cockpits were also supposed to take away the risk of an NPA but all we have is a different set of problems. If you want to eliminate the risk then 16R shouldn't be used at all while the ILS is U/S. That would also imply that if an ILS was installed on 34 then the airport would be unavailable if it required maintenance and the only runway that could be used was 34.