Thanks for all the valuable info. I think I know what I have now, but to be sure, I am going to lay out a circle of each and check the exact measurements. I will for sure save one piece of each and mark them with the curve size for future reference. All of my track is Lionel, and about 2/3 of it looks to be brand new. It is all from an auction that I "accidentally" won, while not paying attention to lot numbers. I am glad I have it now.
Jeff