Sorry I haven't found anything useful to add about Leander. I followed a lead in Adams MA but that one's obit says he spent his life in Adams and went to high School there so it rules out your Leander.
However, I noticed from their children's marriages and other events that you posted that Leander's wife was Almira/Emma Parrot. Her age in the 1880 census was 22, which is very young to have a seven year old. Nevertheless, have you noticed the 3-year-old Almira Parrot living in Plattsburg, Clinton Co. NY in 1860?
https://www.ancestry.ca/discoveryui-content/view/46050461:7667
If that is her and she married in Plattsburg, there may be a church record that gives Leander's father's name.
Bit of a long shot perhaps.