Unusual story of two robot like creatures named Rok and Mog who lived on a dark, metallic planet, lots of clinks, clanks, and spires. Had a sort of Arthurian plot where one of them scales a spire to save a female type robot/machine? I pictured them as metal spider creatures. There was also a humanoid creature who got paid and wanted to buy 'a sex from a Johnny' or something like that.
I believe this is the same author who wrote a more recent story about economics and space/time travel, with immortal space ships with names like Dividends and Profit, that captured the protagonist and time traveled him to avoid an encroaching black hole that was eating the universe. It time looped around with DNA clones of customers or shareholders to repopulate the universe.