@Mike36: When I opened it, it already had the grease versus the heavy gear oil. I did some research which said that yes, those tend to leak the oil, and that 'corn head grease' (or something like that was a better choice), so that that is what I added.
I wish I knew more about my car's history. I bought it in February of 2017 from a person that bought it from an estate. My previous owner hadn't done much besides complete the exterior trim work and changed the steering tie rods. Supposedly the estate owner had done the body restoration.