LeadSled - YGLB is no longer a leased aerodrome; the person running it bought it from the council a while back.
I'm not sure that disallowing access to a runway is illegal, even if there are no safety implications. Plenty of private airstrips that require permission for use; they don't do it as a NOTAM because it's a permanent condition.
I've had a look, but I can't find a source for exactly what a NOTAM can or cannot be used for. Any links?
Ultralights - Goulburn may be unique in that the person who owns the airport is also CEO of the skydiving operation. Nnlike most airports, the person who has the power to put restrictions on non-skydiving traffic also has a reason to do just that.
It's not a great situation, but it's hard to see what anyone can do about it.