I have that car in one of my boxes of out-of-date stuff.
Mine is missing an axle though.
At the very least, you need to trade out the truck mounted horn-hook couplers for Kadee couplers.
There's two ways of doing this. You could use the truck as is and replace the coupler with a Kadee # 24 series underset coupler, and continue to use the truck mounted coupler box.
Here's an example of how I did it back in the day!
Better yet is to cut off the coupler box and use a #5 or a #46 coupler and a Kadee coupler box with a styrene spacer and mount it directly to the body like this. You could use scale couplers if you wish, I don't so I have no picture of that.
The plastic wheels can easily be changed to metal ones for further improvement. I have a few Tyco and LifeLike cars in my current fleet that I have improved.
The Oscar Mayer car has a build date of 1957, so I don't believe it falls into the category of "Billboard Reefer" which were outlawed in the '30's sometime. Folks back then realized that the cars with Schlitz, Miller or Coors painted on the sides had beer in them and often helped themselves to some of the contents! The practice was outlawed due to safety concerns of unloading in a non-approved zone. Not that build date matters to some model railroaders.
Buy the car if it is still available and use it to improve your modeling and weathering skills on a cheap car. I think that I originally paid $1.29 for mine.