Campbell’s kit #353 LCL Freight House
You need one of these on the layout as they were common for Less than Car Load pick ups and deliveries. Lots of little building add potential activity to your railroad. I believe the kit comes with those unpainted crates and barrels that I have not detailed yet. One could scratch build this for a couple bucks, however I acquired this from Campbell’s when I did some work for the company some years back.