Kit Made O Scale Maintenance/ Freight Trolley, Runs. This trolley runs on AC from the overhead trolley pole although it is designed with a center roller to run on 3 rail O gauge track.  ( can be easily converted) The roof & base are wooden and I believe the sides are brass and the ends cast brass( see photos ) It measures 12.50" L x 2.75" W x 4.50 "H.