Note that coupled to the right of WP 8078 is another 8051 series car. These cars were somewhat unique in that the lumber door was located in the 'B' end. The vertical shaft brake allowed plenty of room, so I suppose other cars of the same era could have been this way as well.
One use of photos, such as this one, is in viewing the relative use of good milled wood back then. Flat grain wood was a lesser premium than vertical grain wood, but back in those days the old growth timber commonly used made flat grain wood a much higher quality than the common young growth wood milled today.
Notice that the grooves on this elderly car are still quite tight. What delineates the boards is more the opening of the face of the grains due to flat wood's greater vulnerability to weathering. This is something that toolmaking would be challenged to duplicate--I think that this would be better replicated with painting.