You take an ordinary LGB Bobber like this: I used a cheap old Santa Fe one out of a starter set I found at a swap meet. I forgot to take a pic of it before I started.
Remove all the stuff you don’t want.
Take a rasp and file off anything protruding past the siding on all for sides.
I want to bring this up to 1:20 ish, so I added 1/2" overall to the width by gluing on 1/4" strips.
Cut and file out a larger door on the windowless end. Glue it on the inside.
Glue on siding, “glass” and trim the door. do the same to the other end.
I put the original roof back on and glued some 1/16" strips to it.
Then glued some siding to the sides.
I glued some 1/16" thick by 2" wide roofing to the slats, and some siding to the porches.
I cut a hole for a chimney and glued on some “tar Paper” cloth.
I dug some scrap hardware out of the junk box, made some handrails and finished both ends.
Next I will paint it and show you how it looks behind a log train. Too cold for a train, but here’s the finished car.