The 1928 No 12 Set
The 1928 and 1929 manuals have pictures of models for this set. And the set is described as "Master Engineer's Set, Amazing-Gigantic-Complete" But the set has never been seen and it is thought that it was never produced. Perhaps A C Gilbert was the only one that had the set. Most of the models are large and require a great many more parts than could have been packed into one box. Remember, the last No 10 set weighed 150 pounds. Here are a couple of the smaller models that the manual shows.
Gas Engine. Actual small engines were about the size of this model and were used for power on farms. Enthusiasts still collect and show these old engines, in running condition, at farm equipment shows.
Walking Beam Engine. This model is over 24 inches long. The motor is not an Erector motor.