In the 1940's, these glass lined, air tight silos were a symbol of prestige throughout the Midwest. Then, they began to exhibit defects, especially in the conveyor systems. This, coupled with farm failures in subsequent decades, led to the familiar glossy blue silos symbolizing something else; A farm in financial trouble, facing foreclosure. This is how they got there current nickname, a Blue Tombstone.
Details and weathering are still needed to complete these. They are HO Scale 20 feet in diameter and 56 feet high. A common dimension.