Number Seven Set from about 1929.
Here is the number 7 set from about 1929. There are parts under the green cardboard panel in the bottom of the box. The metal tray sits inside the top of the box.
The seven set will build a Dock Hoist, which uses the metal tray that packs one layer of the set.
This set will build the steam shovel model. Another model is a stiff leg crane which uses the same gear box as the shovel. I started by building the gear box above. More pictures will follow as the model is built.
Here is the hoist unit placed in the hoist plant. It contains the boiler and hoist unit.
The Dock Hoist completed, from the same angle as in the instruction book.
I like to build models that actually work. This requires that the machinery be adjusted to working precision, well oiled, and a power supply provided. The power supply in the picture is an old Marx transformer.