Thanks to Cheryl Morgan (who had local knowledge) tipping me off, I took the regular commuter train out from Flinders Street Station in Melbourne to the end of the line in Belgrave, then walked to the adjacent Puffing Billy Railway and did the full trip out to the end of the line in Gembrook and back.
I'd originally thought I'd join a fannish tour group, but discovered later that all they did was drop you at Belgrave, where you rode only as far as Lakeside, where the bus picked you up and headed off to the next stop on the tour. I'd rather stay on the train when possible, and I did.
My only regret was that as it was the long trip, there wasn't time to check out the steam museum along the line. If I go back, maybe I'll get a chance to do so.
It's Australian Open time, so we get periodic "atmosphere" shots of Flinders Street Station from where the metro train out to Belgrave departed, which makes me all nostalgic for that trip in 1999.
My trip on the Puffing Billy was one of the highlights of that 1999 trip, although of course winning the 2002 Worldcon bid was pretty good, too.