Why do you say the catchment is there ? Why specific areas are you referring to ?
I don't doubt there is a market for services but I am unsure how big a market and to where passengers might be headed ? Are we to assume these trips will be to Ballarat.
Echuca has up to eight V/Line services a day including two trains - http://www.vline.com.au/pdf/timetables/echuca.pdf/echuca
Population of Echuca - 13,652http://profile.id.com.au/campaspe/population?WebID=200
Population of Stawell - 8,270http://www.liveinvictoria.vic.gov.au/living-in-victoria/melbourne-and-regional-victoria/west-victoria/stawell#.VGFytTSUeSo
Population of Horsham - 15,890http://www.liveinvictoria.vic.gov.au/living-in-victoria/melbourne-and-regional-victoria/west-victoria/horsham#.VGFy3jSUeSo
Horsham has seven V/Line services a day, not including the twice weekly 'The Overland'http://www.vline.com.au/pdf/timetables/nhill.pdf/nhill
However Horsham has no daily rail services, yet it has a higher population combined with Stawell than Echuca combined with Elmore and Rochester.
Bendigo and Ballarat are about the same size, so they may be included or excluded from the discussion.
I believe its something of a fallacy to say the Echuca has a lot higher number of day visitors by PT because if PTV and V/Line really wanted to increase the tourist market they would accelerate the Echuca trains by making them limited express to/from Bendigo, implementing the higher operating speed from Bendigo to Echuca now the level crossing protection project is 'complete' and the re-joining of the PN sabotaged and cut rails to the Echuca wharf platform would make the arrival in Echuca a real event for tourism.
This could potentially shave 30+ minutes from the journey.
None of these incentives are showing any inclination at all of being implemented with any urgency.
Hence my argument that Horsham would support a re-introduced daily rail service with a change of services at Ararat and after surveying, perhaps a trial of operating the SG service to Geelong/Melbourne.