BML #15 (exB&M #2360), an 1897 baggage-mail car acquired from the Boston & Maine
RR in September, 1927, served the B&MLRR as its Railway Post Office (RPO) until
it was converted to a tool car in December, 1949. (It was replaced as the line's
RPO by BML #73 (exBAR #563) which was acquired from the Bangor & Aroostook RR
in June, 1948.) The B&ML's last mail run on February 5, 1960, was also the last
run by an RPO operated by a short line railroad in the United States.