Tons of drums? The reason drums get turned isn’t of oblongness, its for taper from the inside to the outside. The inside is held together by the center of the hub, but the the open side will expand with use as it has no support.
I have to respectfully disagree. It is true that rotors can deform due to taper from the inside to the outside but it’s also true that they can become oblonged. The reason why I state that is from measuring some of them and watching the cutting bit on the lathe.
By use of the word “tons” that is defined as “a bunch”. 
That park brake test is still a legit test as far as determining any problems on the park brake end of the car; which is usually the rear. It’s still possible to have a shudder or pulsation caused by both ends but the park brake test will verify whether that particular end is involved in the complaint or not. Assuming it’s not a vehicle with separate park brake shoes of course.
So in response to all of the above…I am going to try getting new tires. From reading all of your comments, it seems as if that might not help, but it’s worth a shot to me and I wouldn’t be wasting money since it needs to be done anyway. I have had 3 different mechanics check the brakes, rotors, etc. and no one can provide a clear answer to what it is. Thanks for all of your help!
So you aren’t going to at least try a couple of hard stops to see if that works? Spend money is your first option?
I can try the hard stops, but I need the tires fixed anyway.