A little background. I invited several detectorists to explore area around my colonial house. So far, except for a few wheat pennies, they have found about 30 pounds of iron. Largely farming relics. About 6" down, they found this. It may be important to note the house has never had steam heat. The shape immediately suggests to me some connection with the thermostat in an auto's cooling system. I think it important to note that it has a "bleed" allowing fluid to flow out of it, perhaps to a pressure or temperature gauge. It has a part number, but it is now illegible. Anyone recognize it?