I obtained some information on 36" gauge Porter locomotives in 1997 from the following address.
National Museum of Science and Technology
P.O. Box 9724
Station T
Ottawa, Ontario
K1G 5A3
Curator for Land Transportation
(613)-991-3082
I provided the locomotive's gauge, wheel arraingement, year built, shop number, cylinder size, & drive wheel diameter, With this information the museum was able locate spec sheets for particular locomotives. They were also able to locate drawings of some of the locomotives I was interested in. In a few cases, the spec sheets lead to different locomotives, but of the exact same design.
Cameron