Found these rascals in the split head I'm replacing.. thought it was too old to be stoned.. .
Owner years ago didn't have any cloth or screen to put over the radiator opening.
He had a pan of fresh river water, and a few of those stones at the bottom of the pan spilled into the filler neck, straight into the head
Stone River, wider than a mile...
Makes sense People just kept them going in those days. Tim
mine has keystones in it ha,ha. charley
I'm probably lucky that's ALL I found in there!