Those open coaches remind me of the passenger cars Cedar Point uses (other amusement parks too, probably). Seeing crosshead pumps on those Porters at such a late date is a bit novel, too. Those were fast disappearing by the 1890's. Another interesting detail is how one engine has a headlight and the other does not. I assume the heaviest traffic was mostly running downhill?
Porter did a large business in replacement parts. Even early on all its engines were built to standard templates and small companies that lacked full shop facilities could order out the majority of parts required. This ran contrary to the norm on many bigger railroads that custom made everything as needed. Porter engines do not look particularly nice by conventional metrics but they have a thoughtful "form follows function" layout that I appreciate on its own merit.