O Scale. Model comes pre assembled in nice colorful packaging some parts may become dislodged during shipping these parts can be simply glued back on the model. Since 1947, hobbyists and collectors have made Plasticville U.S.A. products their structures of choice. Now, in addition to our traditional, easy-to-assemble kits, Bachmann is pleased to offer these pre-assembled Plasticville U.S.A. buildings.