The main difference I can see is that most 1800s American passenger cars had wood sides. This one looks like it has been rebuilt with steel sides.
On the other hand, well-maintained passenger cars of the period had tightly fit siding with good paint, usually varnished, so the boards wouldn't really show. Nothing like even a new boxcar (not varnished), and certainly not the weathered wooden cars of the 1940s and later.