This is a 3mm:1ft model of a Great Western Railway O35 open wagon (medfit). Only 2 were ever built, and they were completed after WW2 by British Railways. They were intended to carry DX containers (also uploaded) loaded with blocks of Portland stone. You will need scale 3'1.5" diameter (or thereabouts) wheels on axles which are 20mm between pinpoints (also uploaded). Triang, intermediate or fine profile wheels should all fit, as long as the axle is 20mm over pinpoints. There is a joining tag between the v-hanger and the middle of the tie bar on each side, for stability while printing and processing. Carefully cut these out when you receive the model. Replace the tie bar with a strip if something else if you break it, or it is bent in spite of the tag.