The complete Porter lovomotive roster is now for sale in a book: "Porter Steam Locomtives light & Heavy" published by the National Model Railroad Association, and much cheaper to members. It gives mt/year construction date, gage, cyl size, name of railroad or contractor, a location of shipment, some of class and some of weight.
what is hard to trace are the non-railroad buyers such a contractors. I also have a searchable computer list, but it does not have locations.