Since his wife Emma was born in Massachusetts and Horace's family had lived there, their marriage may be recorded in Greenfield (Franklin County.) Census data do not address maiden names or other marriage information. I do not have the tools to search for Horace in 1930 data or otherwise look for a death date.
More tidbits from census: Horace was a butcher by trade. I could not find son Guy in 1920 data, but son Louis may have been in Lowell Massachusetts, where a Louis Prefontaine b. VT age 34 was residing in a boarding house.