by jbvb
AFAICT Rockport, ME never had a railroad, so NYC - Rockport would be the end of the B&M branch from Beverly through Gloucester, MA. That and the NYC - Portsmouth sleeper were most likely cut out of the State of Maine at Lowell and moved to Boston in a New Hampshire Division train, then put on Eastern Route trains. There wasn't either a switcher or an appropriate track layout to route Portsmouth via Rockingham Jct.