I just came across your inquiry about Peter Chernobieff, the son of John and Vera Chernabieff. I, too, had been puzzled about what happened to him after Vera's birth. The reason that Pete is hard to track down is that he changed his name to Peter Sharon. He was living in Sacramento in 1942 when he registered for World War II as Peter Sharon, and died as Peter Sharon on July 13, 1956, in Placer County, California. I don't know whether or not he remarried, but he was apparently single in 1942, when he was rooming in Sacramento with a guy named Leo Kahn. Hope this helps!
Marshall E. Bowen