Who is Wilbur Oxnard from Factotum and what is their importance?

An elderly gray-haired man with one arm, Willie is an eccentric millionaire living in his father's crumbling mansion on Alvarado St., Los Angeles. He provides three women, Laura, Jerry, and Grace, food, a bed, but no money, and allows drinking only when he is drinking. Willie can be nasty when drunk. He gives Jerry $50 a month for life, extorted from him one night when he is drunk and horny. Believing that he is dying, he wants to get in as much sex as he can beforehand. Willie needs a librettist for his unfinished opera, The Emperor of San Francisco, and is happy to welcome Henry Chinaski into the group through Laura, whom Henry picks up in a bar. Henry notes that Willie's living room is strewn with coins and dominated by an electric organ.