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Asking for a friend.
Novel (possibly novella or novelette)
Australian/Melbourne author (likely but not certain. It shows a lot of familiarity with Melbourne).
May have been published overseas as well.
Published circa 1976 to late 1980s* (*It was read in roughly that time frame AND there's a mention of Melbourne's Valhalla Cinema as still operating, and that was its time period. http://en.wikipedia.org/wiki/Valhalla_Cinema,_Melbourne).
Present day (late 1970s - 1980s).
Marginalized by society.
He is increasingly ignored.
Eventually he actually disappears from our universe and enters an alternate version of Melbourne.
While there he meets a girl, also marginalized, also from our universe.
NOTE - It's possible that the alternate universe appears black and white to him.
Unsure if the alternate Melbourne is unpopulated before he meets the girl, but we think so.
Can't remember if romance ensues, but it probably does otherwise what's the point?
Can't remember the ending.
I'm asking for a friend, so there's probably not much more I can tell you.
Thanks for reading.