The top rack is of two pairs of sliding bolsters to seat under the ends of tracked vehicles loaded on the Rectank WW 1 & 2. The other racks are the small design of bolsters fitted to many Rectank wagons in peacetime use for general goods service. I had to link them together into fours to meet the minimum printable bounding box, so they will have to be parted from the sprues with a razor saw or similar, and the rough edges filed down. These ends would have been sawn ends of timber, so a smooth finish is not essential. You could use the conventional bolsters on other bolster wagon projects.