Progress. Following the advice of Thomas, I ordered 1000 coffee stirrers to use for the window frames and doors. I must say, I am happy with the door lintel. The window frames aren't amazing. I tried inserting them actually into the holes I cut, but wasn't too happy with how that turned out. I will investigate other options.
I am a complete convert to bird sand though. I love the texture it has given. I applied PVA quite thickly on the front facade of the building, making it rougher than I intended. But the other sides of the house look just fine. I can't wait to decide upon a roof, then find a cork board to base it on.