So far I've found 21 US newspapers that had Sunday editions with complete novel inserts. The range of years is 1919 to 1967. Nine of those newspapers used the Canadian Star Weekly novel, just changing the name of the newspaper on the front page. Here are the nine:
Akron Beacon Journal
Bangor Daily News
Bangor Sunday Commercial
Chicago Sun, The
Long Island Sunday Press
Newark Star-Ledger
Philadelphia Record
Sunday Patriot News [Harrisburg, PA]
Washington Post
Note all are in six Northeastern and Midwestern states - New York, New Jersey, Maine, Ohio, Illinois, Pennsylvania and Washington DC. The other twelve newspapers are also in these states plus Michigan. Odd that none of the newspapers in the other 41 states appear to have published novel inserts.
Here are three Star Weekly novels.
June 2, 1945 - Angel Without Wings by Martha Ellen Wright (Doubleday, Doran, 1943)
October 21, 1944 - Captain Millett's Island by Katherine Newlin Burt (McCrae Smith, 1944)
October 10, 1953 - The Case of the Hesitant Hostess by Erle Stanley Gardner (W. Morrow, 1953)