In a previous post I mentioned an Ansett 9 diverting into Groote after having issues with some dodgy weather in Gove. That would have been between May and October 1980. They were operating CNS-GV-DRW mid-morning and after a couple of goes in Gove had no gas for Darwin and popped down to Groote - for a couple of days.
Gove definitely didn't have a tower then only Flight Service (and what a top bunch of blokes they were.)
I believe, from memory this was the incident that led to Provisional TAF's and the requirement for an Alternate associated with them.