Howdy folks,

I just bought my 66 Cutlass. It is more and more appearing that the 66k mileage on the odometer is correct; it has never been beaten,

The "top" of the half sphere

The "bottom" of the half sphere
just parked for years. While draining/cleaning the gas tank, I found five half spheres (zinc-coated steel? I think). I am attaching two pictures. There is an M on the "top" side of the sphere it the flat side slid around in the tank.

If I had to guess, these were put in the tank to reduce sludge or scale by sliding. They made no noise until I pulled the tank and cleaned it, not that it needed much .