George is living with his parents in the 1940 Federal census on North Roy Street in St. Paul - same place they were in 1930. He has three years of college and is a laborer.
Interestingly, in the same city and zip code where his brother James K. died (El Cajon, CA 92021), there was a George Edward Martin, b. 28 Aug 1909 in Minnesota and died 17 Jun 1972 in El Cajon. However, the Minnesota birth index says his mother was Anderson and his county of birth Itasca and the day and month of birth is a few months different. And his gravestone inscription in the El Cajon cemetery says "father & friend," so he must have been married. So, similarities only.