You might find that people would be interested in, and even eager, to play in an older RPG system, simply because of the nostalgia factor. I suppose I'll never actually run a Chill game again, because no one these days remembers that system, but I might run a nostalgia 1st ed D&D game, or Marvel Superheroes (talk about an easy system!), or 2nd ed Vampire, for instance. I don't know about UCon, but I know that one of my friends who had just self-pubbed a game system managed to fill a table at Vericon for a session of his new system.