You must be logged in and verified to contact the designer.
This is a pair of bogies designed to be just right for the N-gauge/2mm WD (WW1&2) Rectank model which is currently sold as a resin casting by GRAMODELS. These bogies should be an improvement over hacking about with the old Graham Farish diamond frame bogies which are the wrong shape, too high, too long in the wheelbase and have a rather large coupler arrangement which will stand a long way out past the headstocks unless you cut the spring box out. If GRAMODELS himself offers a bespoke bogie for his Rectank then you won't need this one. His (current) Rectank model has the bogie centers slightly closer together than on my 3D printed WD Rectank, so the bogies are not interchangeable (I have uploaded bogies for them too). You will need to decide whether to use the self-acting N-gauge couplers, or fit NEM couplers in the pockets provided at the other end, and you will need to cut off the ones you don't want so that there is clearance to turn the bogies under the wagon (unless you are using the lifting N-gauge couplings AND choose not to fit angled trussing on the two cenral lines). The correct wheels would be 8-straight-spoke 5.5mm diameter, but 6mm should still clear the underside most of the time. Parkside Dundas 5.5 mm curve spoke will probably look OK too, and also run nicely. My 5.5mm 8-straight-spoke 3D printed wheels are another option, but being light and a bit short on flange they don't run as reliably. Finescale 2mm wheels on 14.8mm axles should also be OK.
As a bonus, this model includes a pair of oblong parts designed to boost the depth of the cross-members under the Gramodels Rectank, with holes at the correct widths to support short lengths of stiff wire to represent queen posts and loading jacks. Carefully separated from the sprues which join them together, cleaned up, drilled to take the wire you use for the posts and jacks, and glued to the underside of the wagon in the right places, they should help you construct the rod trussing under the center of the wagon from lengths of very fine wire bent in the right places and glued to the queen posts. Take care not to foul the clearance the wheels will need to take, especially on sharply curved track.