This building is from Ertl's set 4221 'Cow Town.' It was a perfect starter town for Old West gaming, coming with piles of fencing and accessories. It's out of production, but can still be found on eBay.
The kits are made from Styrene plastic and glue with plastic model cement. (They are snap-fit and don't need to be glued at all.) They are well engineered and well detailed, and although the big kits have many parts in common, they look quite different from one another.
Doors open and close, and roofs come off to allow access to the interiors. In other words, they are nearly perfect for gaming.
The only real downside is that some parts are made from polyethylene, so don't glue or take paint well.
In this case, it was the doors, so I made replacements from styrene sheet.
Because these are designed for kids, the hinge posts are pretty thick. Searching for suitable wire, I found an old metal coat hanger, and the wire fit perfectly.
The body of the door was made from styrene sheet with boards scribed in, and framing was cut and applied over top. The framing also covers the hinge, which sits behind it, making a stronger hinge joint.
I added an awning to the front, made from a frame of 1/4 in square styrene, with a styrene sheet awning. Shingles were applied over this, also made from styrene sheet.
The playbills on the building front are actual posters from a period theatre, printed on my computer.