Duncan's hut on wheels is lovely but while the box picture shows a chimney, I couldn't find one inside.
No matter, a brass tube off cut soldered to the roof and then fiddled to be upright soon sorted this out. It's probably better than a whitemetal one anyway as you can see it's hollow.
Looking from a normal elevated viewpoint, the lack of a floor inside is a big problem. While I appreciate that these things weren't kept in the best condition, you shouldn't be able to see the ground!
Sliding some pre-cut Daler board in was fiddly and if you look closely the sheets overlap in the middle, but at least looking in through the top of the door shows darkness now.
Inside, I'm just painting it black. An interior would be lovely but you won't see it on the layout so I'll skip the scratchbuilding.