G'day y'all, more of a lurker than poster, but just to clarify...
Airservices Australia install and maintain all navaids, ILS and approach lighting. The airport authorities have nothing to do with them, other than (carefully) mowing around their bases.
The airport provides all other airfield lighting, visual approach systems (Papis etc) and wind indicators.
If an ILS cat III is to be obtained (and it would save a lot of chaos come Fog Season), any
needs to be done to the Airservices wall, rather than that of the airports'.
Cheers!
Worrals