Steve, the latest reference to the Victorian Longtack Titles I can find is 2003 when John Jorgensen, Jason Stewart and Louis Meyers finished in that order, a check with MVIC should help, I can't find where they were held, but suspect it may have been Wangaratta.
As far as track length, due to MA meddling with the GCRS, there is no such thing any more as Longtrack or Shorttrack, simply just Track.
In my humble opinion, any track length under 800m, ie a Halfmile, is not Longtrack. Having said that any Track meeting on a 600m track , a third of a mile or so like the old Sydney and Melbourne Showgrounds, is the next best thing.
Longtrack, to me is a sport where high speed, power and the size of the rider's ticker counts, whereas the shorter versions are so much more reflex and reaction time focused.
Good luck, I'd like to see it happen, where ever.
Foss
Just my two bobs worth !!