[JoeFromPA]

Sorry, I didn't mean to insinuate that. I have no idea when it started. I received the car from my father about a year ago and have been slowly sorting it out (it was in good condition, just a handful of things to take care of).

The one additional factoid I have here is that the issue was still present when I had a set of 17" wheels/tires on for cold weather times - but it was different in severity, speeds, etc.

So either both set of wheels are out of balance somehow, or it's another component.

I'm about 80% sure it's somehow balancing related - the fact that it changed with wheels/tires at all indicates it's related to their rotation. However, if there are things I can inspect first to make sure that's accurate I would vastly prefer too...