Three
months, I think, Smauggie

Lightning-fast Australia Post took 3 days just to get an outsize envelope from my local letterbox to a street address in the City last week.
I know nothing about the stamp or cover, but this Web site
http://www.stampsofvictoria.com/
might help.
By a nice coincidence, I was down in Geelong yesterday, for a family occasion. Geelong has probably declined in importance since the time your cover was posted. Coming from there, the
Lightning was probably carrying wool.