I found these in an antique store in Dillon, MT. They look to have been on that board for many years and it appears to be the board they were mounted on when in service. They have a little soot on them and were definitely in service. Each is about 10 inches in diameter and about 3 inches thick at the center. they are mounted on a cast iron footing which looks to extend through to the top creating a threaded pin hole. A metal plaque reads General Electric, Type AE-99. I'd appreciate any information about these as well as a rarity assessment and value. Thanks, will post two additional pics.