Tony,
The 'speckled' truck frame is I believe one of the 1st castings . It was sent to you in error. We since adjusted the color portion of the mixture. That is the difference between the two. Bill was looking for that casting so it would not get sent out. Somehow I shipped. I will gladly replace if you want w/ another from the next batch. Adjusting the color also changes the flexibility ( more ridged ) piece. Harry