This is an N-gauge model of the superstructure of a mesh-sided open wagon, converted from an OAA. They are used to carry building blocks. The model design belongs to AmelieEloise (uploaded here with permission) and it used to be available on the Shapeways Marketplace until 2024. The model fits on an old Graham Farish N-gauge 19' wheelbase 4-wheeled chassis (spares production discontinued around 2018) so you'll need one of those, and I don't know if there are other options. You will also need to source some suitably fine wire mesh, which you can get from one or more UK suppliers, for example, in convenient sheet sizes (A5-ish) from which to cut smaller pieces.