YouTube credits:
Always Trains HD:
SFBR 23 (alco S2) Switching With a Leslie s5t
https://www.youtube.com/watch?v=NhyFvrGdhx4&t=1s
Other credits
(Not sponsored)
DL-109 Video Footage:
(DVD) New York, New Haven & Hartford Railroad Volume 1 - A & R Productions
Note: the original publishers website (www.classicrailroadvideos.com) seems to be defunct.
Picture of Buffalo Creek HH660 #43
www.Wikipeida.org user Prrbaldwin
https://creativecommons.org/licenses/by/4.0/
Picture of Midland NW2
www.wikimedia.org user Russel Meier CC by SA 3.0
https://creativecommons.org/licenses/by/3.0/