As for information on the line from Kenwood to Machanicville, I recently found several pictures in publications by General Railway Signal, that show the CTC machines installed in Albany, around 1937. You can see them at:
http://i232.photobucket.com/albums/ee5/ ... DHCTC2.png
http://i232.photobucket.com/albums/ee5/ ... DHCTC8.png
I believe the area covered runs from the north end of Union Station to Waterveliet Junction, on the first machine, and from there to Mechanicville on the second. The linr crossing on the right side of the first machine looks line the line coming across Livingston Avenue Bridge.
I've recently seen mention of "the Meneands Team Track", which sounds line the tracks near Broadway. There was also a short branch nine, running northeast from there, to a group of buildings that now form part of the Central Farmers Market, near the current Route 378 overpass on Broadway. Google Earth still shows the ROW of the branch, and the 1955 topo map shows the arrangement of tracks around the terminal. I found many different topo maps and photos of the area at: