This is the link to the Ipswich Library -
http://www.ipswichlibrary.org/archives/guides/obituary-indexI found an Adam PRZYBYSZEWSKI died Jan 6 1949 - obit on Page 3
Maybe you could email library and see if they could send you the notice or email town clerk and see if she will give you info from death cert or you would have to go to Mass Vitals and look at certificate yourself. Thinking it might have wife's maiden name - but that info would only be as good as what the informant knew.
I did not find wife's death notice.
Margaret
Edited: On the 1940 Census - William's brother Stephen(b 1893 Russia) is in Ipswich - last name is Prisby.
I've attached Stephen's marriage so you could see spelling of his mother's maiden name.