I got the one-story freight house primed last night. While it was drying I turned my attention to the two-story section of the building. In later prototype photos this structure had plywood sheathing added to the first story section on the track side of the building. I was going to do my model that way until I came across a photo Frank Quinn photo from the December 1990 issue of Trains* from my modeling era that confirms (1) the clapboards extended all the way to the ground, no plywood sheathing, (2) the building was in dire need of a paint job and (3) there were a couple of small freight doors on the side of the building (these were covered over when the plywood sheathing was installed.
I decided to build this portion of the building from basswood clapboard (Albert Scale Lumber, 4" HO clapboards). I spent some time last night with Hunterline stains of various colors trying to match the overall appearance and coloration of the building in the prototype picture. I think I'm getting pretty close. I find the wood stains hard to control since the wood grain plays tricks with the coloration. I think using styrene with brush-painted colors would have been easier.
*The article indicates the location is "unknown" but it's pretty obvious to anyone who has been to Waterbury or looked at photos taken in the steam era that the photographer was standing between the station and the foundry building. You can see Frank looking out from one of the window openings!