Lionel certainly hit a home run with their milk cars years ago. I’ve managed to pick up a few brass cars to add some variety to my Rutland Milk train. They ran a number of 50 ft. Woodsided cars. I picked this up on the auction site fairly cheap. It had the Pfaudler lettering on it. Used a tip from the forum of using scotch tape to remove the lettering hoping it wasn’t cleared over. It did the trick. I had planned on giving it a fresh coat of Pullman Green anyways.
Many of the lessee cars from the 30’s up until the war. Had steel placards for the dairy they were hauling to. These were bolted to the sides. Most were removed for the war effort and really not sure if the were ever re lettered. I wanted to simulate that. I bought a sheet of .005 steel. Cut, painted and decaled. Really didn’t want to glue them to the sides. I had some rare earth magnets and glued some stripwood to them so they would be easy to move in place. Place the placard on the side of the car where you want it. Maneuver the magnet in place on the inside of the car and like magic. The sign isn’t going anywhere.
Never been a fan of 2 rail trucks or wheelsets. At least on most things I’ve purchased. Not 100% derailment proof and most don’t seem to roll that well. I used Lionel’s new milk car trucks. These come apart easily compared to the older ones. You are going to use just the side frames. A piece of brass stock and 3 precisely drilled holes. You will need longer screws. Below is an Atlas Commonwealth truck. But it’s the same process.
These will mount up pretty much like the factory truck with perhaps some washers needed or a thin shim for the coupler. Pretty much the factory ride height with a truck that really rolls and is 3 rail friendly.
If your looking to add some variety to your milk trains. Give the brass cars a look. If your patient and up for a project. They can be found at reasonable prices. All I’ve done except for one steel car have been fairly easy to add Lionel trucks to and retain close to the same ride height. The car below. The Lionel truck actually has a long wheelbase. Just enough that the mounting hole needs to be offset for clearance of details. I had to do this to a Butterdish car as well. They still track perfectly.