Have you ordered his death certificate from Dade County FL? Still might have a Social Security number on it. Have you tried the Dade County Veterans Affairs office to see if he filed and used any VA benefits due him?
I find a John E. MacCurdy b. abt 1914 age 21, Nationality-American, listed as a crew member (listed position as D.B.) of the ship "M.S. Tampa" that arrived from Calcutta, India to the port of NY,NY on Sept 22, 1935. He was dischargd upon arrival, signd on 6/4/1935 in NY. NY. served 1/4 of a year, also claimed his race as Scotch. Shipping line was American Pioneer, owners were U.S. Shipping Board and Local Agents were Roosevelt S.S. Co.