A great deal of Portland Company drawings (for all of the Two Footers) exist at the Maine Historical Society's archives in Portland, Maine. The Two Footer drawings were all organized a number of years ago, and have been cataloged. Portland Company built all the freight equipment for the WW&F, and many of the locomotives.
Baldwin drawings still exist (I don't know about for our locomotives), and I think live at RR Museum of Pennsylvania, or maybe the DeGolyer Collection at Southern something University in Texas (Southern Baptist or Methodist?).
Jackson & Sharp drawings exist, I believe they are in a museum collection in Wilmington, Delaware. I forget the name of the place.
Vulcan drawings for #10 exist, I don't know where they came from. We have those.
That leaves Porter, and I don't know about them.