I did not take time to read the entire piece, but well done in general I think. As a Sumpter Valley Ry. aficionado I'll point out one mistake. SVRy mikados 19 and 20 later WP&Y 81 and 80 respectively were not among the engines acquired by the US army for the use on the WP&Y as suggested in the article. They were sold by SVRy to the WP&Y at the beginning of 1941 before the war for the US had started.