This kit can be built to represent one of several iterations. Originally built pre 1885 for the DSP&P, they underwent several upgrades to evolve into what the C&S had at the end of the narrow gauge operations. To this end, the kit has options for blades, sill reinforcements, railings and of course lettering. Trucks that are supplied in the kit represent the initial UP Swing Beam Type "C". If you check your photos of C&S 015 you will see it equipped with C&S 1902 4' archbars. These are available from several sources so just ask!
Kit comprises of laser cut woods, etched brass, 3D printed ABS, injected plastic, and brass wire. Assembly is straight forward. You will have to make some up front decisions regarding which variation you want to end up with. As mentioned, kit includes trucks for the UP Swing Beams.