Atlas has announced an N scale double sheathed boxcar in Northwestern Pacific. Did the NWP have any interchange cars by the early 70s? I don't remember ever seeing one, none of the photo sites I have links for list one, and a 1972 "Guide to Railroad Officials" says they had "81 misc cars", while interchange cars are usually listed by that guide as "## freight cars".
If they did have interchange cars, a second question would be, "what kinds?".
Thank you.