Don't kid yourself; they're all made in China and imported.
I bought one too, not the same model, but I knew what I was getting into. I plyed, caulked, insulated and painted the inside. I put two coats of wood preserver on the outside, put a window in one wall, moved the roosts, put window vents in (as I didin't believe that one vent was sufficient - especially in Winter when I don't want a breeze) and replaced all the hinges with better ones. Unfortunately, weather sealing the nestbox didn't prevent the water from dripping in and the preservative didn't stop the roof from rotting, so it's all getting painted now. That seems to have stopped the leaks, not a minute too soon. The thin ply they use under the roof is cracked and damaged. Hang on, I'll get pics for you.
It was the largest I could find, but I wouldn't house more than the two girls I have in it (a Sebright and a Friesian). I put a small feeder in one of the nest boxes, to save on space. It lasts them about three months (they do free-range, though). You can see the beginnings of my paintwork. I had done the roofs as a matter of urgency, but am only now getting around to the walls now the rain has stopped.
The last picture shows the modified roost locations. With some thought, I should have ditched those rerches altogether and put in longer ones across the long side, so they can have the vent open at night without getting chilled.
I also have no idea how to secure the door from foxes :-(
PS. I also removed the tray. I park my wheelbarrow in front of the coop and push everything out using a hoe. Easy peasy :-) I hose the coop down twice a year.