I got this a few months ago posted in 'upper berth' wondering what it was:
After finding out what it was I searched online to see if anyone had every painted/finished one but came up empty.
I decided just to paint and weather it as I figured it would have been:
I semi dry-brushed barn red onto the body, then painted the tarpaper patches with a grey-black. The windows were done in vintage white. I used three different tamiya wood colors on the boards.
I then used Tamiya's 'panel liner' in both black and brown as a wash to go between the boards and siding and add some depth.
The backside got the same treatment, with more boards to color and weather. I used some microscale window liquid for the windows. When I place it on the layout I'm planning on putting a flickering LED in for lighting to simulate an oil lamb or an open wood stove.
The original roof was not useable to I fabricated a new one using some basswood sheet. I used either Campbells or DR Ben's corrugated roofing and weathered it with three different rust colors, two airbrushed and one wash. I made some patches from smaller corrugated roofing and applied 'tar' sealate around them.
The last thing I did was airbrush an overspray of Vallejo 'dirt' to tie things together and tone down a bit of the starker weathering colors.