To start with, I used one of the roof pieces from the schoolhouse to cut a floor. I applied some white glue and sprinkled on a liberal amount of tea leaves.
Once that was dry, I took another look at the front of the greenhouse. The off center windows had to go! This small plywood is not easy to cut and it took many passes with my utility knife and metal ruler before it finally gave in. I wanted to line up the mullions with the rafters in the roof and also add some trim, so I dug around in my stash of wood strips and found some 1/8" that looks nicely in scale and would work perfectly. Here's a before and after:
I brushed on a coat of white paint and put it aside to dry. While I was waiting, I worked on the interior of the greenhouse. Once the front and roof are glued on, the interior will be inaccessible so I worked on a bench and some shelving pieces that I cut out of scrap wood. I glued them in place and started thinking about my plant arrangement.