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A pair of the GWR O30 wagons with chassis included, but without wheels (someone requested this). There are some microscopic alterations to the brake gear compared to the previous model, including a dimple in the back of the pushrod cams to help locate the ends of a brass wire (or similar) crank shaft, and a tiny stud on the outside of the V-hanger on the side requiring a cam to reverse the action of the brake lever, which should make it easier to seat the end of the lever on this side. I don't think it would be practical to print the crankshaft as it would have to be a lot thicker than I would want, especially after painting, and it would be fragile too, especially when putting the wheels in.
To complete the models, clean them thoroughly, fettle out the conical recesses for the pinpoint axle bearings until the wheels fit in and turn easily, and clean again if necessary. Next, add the brake crankshaft and levers (from spares) as described, paint, put the wheels back in, and fit couplings and/or coupling hooks. Door bangers on the solebars (too flimsy to print) would be a nice additional detail. I sugest Peco 8-spoke wheelsets for N-gauge, and 8-spoke on any axle around 15mm long for 2mm finescale. Despite the higher cost, I recommend ordering in Frosted Extreme Detail, as the surface finish should be smoother than in Frosted Ultra Detail on the larger body panels and door.