I have finally settled on a color scheme so I could paint the frame and mount the engine. The body of the truck will be Krylon Almond, the rims are Krylon Boot Brown and the frame is Antique Bronze. One of the stock photos I have shows a light colored truck with "Goodwin Sand and Gravel", so I think that is where I am headed.
Very little of the engine from the Monogram Mack AC was used, its mostly kit bashed and scratch built. Advertising booklet from the era shows good detail on both sides of the engine, so I felt compelled to duplicate it. The four cylinder engine has a dual ignition with 8 plugs, still just a bit of plumbing to do.
So that's it, still plenty left to do.