Progress is fine, but it's gone on for too long.: Caterpillar #11 Auto Patrol grader

Nice thing to display beside the front door of the Montreal office of the Caterpillar corporation.
The Caterpillar #11 Auto Patrol grader was introduced in 1931, originally in grey, but for visibility the corporate colours were soon changed to yellow, the tandem rear wheels were came along about 1934, as did the diesel engine.
In 1939 the model was replaced by the (wait for it...) #12.