This is an S scale kit for the Canadian National Railways center cupola, steel Framed Diamond Road Flanger. This small group was identical to the center cupola, single sheathed flangers built in Moncton between 1926 and 1938, except that they had an extra layer over the steel frame.
These cars in CN's 56278- 56280 series were built at the CNR's Moncton Shops in 1927. They were double sheathed with the high windows like the single sheathed cars. For the single sheathed cars, we have another kit: https://www.shapeways.com/product/W2F79WXWD/ho-cnr-single-sheathed-center-cupola-flanger .
This kit includes the special diamond flanger blade, stirrup steps, wind deflectors for the cupola, brake cylinders and handbrake wheels, and a choice of smoke jacks for coal or oil fired stoves (H shape for oil). Extras of the stirrup steps and brake wheels are included.
The kit is available in FUD acrylic. The builder will provide trucks, couplers, screws, paint, and lettering.