Jane's mother was living with them in the 1940 census. John was a proprietor of a "tap room".
I looked at the Social Security Death Index and find a few possible candidates:
John Moylan b 10 Jun 1901; "last residence" = Dorchester, Suffolk, Massachusetts (this means where the last social security benefits check was sent). Died April 1875 in Massachusetts. I could not quickly find a Mass. birth for him.
John Moylan b 19 Feb 1902; died April 1948; SS# issued in Missouri bef 1951. He's also found in the California Death Index; indicates a Missouri birth and a Riverside, CA death. Probably not your man given the Missouri birth (1940 census says your man was born in Pennsylvania).
John Moylan b 24 May 1902; d Dec 1962; SS# issued in New York
John Moylan b abt 1900; d in Queens, NY 21 May 1946
John Moyland b 28 Sep 1902; d Jun 1967; SS# issued in Massachusetts. Not your man; his birth is found in the Massachusetts VR (born Somerville, MA)
John Moyland b 31 Oct 1899; d Dec 1958; SS# issued in Philadelphia, PA. Despite the 2-year difference in birth year, this location is much better suited to your John Moylan.
John Moyland b 30 Sep 1903; d Aug 1970; "last residence" Olyphant, Lackawanna, Pennsylvania. Another good candidate despite the 2-year difference in birth year.
I did not find an SSDI record for his wife Jane.