Tom Henderson, owner of Sidetracks, and former Houston S Gaugers club member, donated to the Houston S Gaugers this kit by American Model Builders. It is kit #78, the "Interlocking Tower". The Houston S Gaugers have a set of modules that form a double-track wye. To formally protect those intersecting tracks, a tower with tower operators are necessary. This kit will do nicely. The laser-cut kit comes in a nice, small plastic bag.
This photo shows the parts that were found in the kit. The kit comes with a 6-page instruction sheet, which covers basic kit-construction advice, identification diagrams for the various parts, the construction instructions themselves, and a page with drawings showing each of the four sides. The kit parts consist of laser-cut basswood, laser-cut peel-n-stick sheets, laser-cut cardboard, laser-cut window "glass", and a white-metal vent pipe/smoke stack.
(external link: American Model Builders)