201768-18-1, WWII Warbird Curtiss-Wright Engine Special Tool

WWII Warbird Curtiss-Wright Engine Special Tool. P/N 201768-18-1. Overall length of the tool is 14 5/8". Socket outside diameter is 3 1/4", inside diameter is 2 5/8" and center hole diameter is 1". Unsure of type of engine it is used on, (R-1820, R-2600 or R-3350), or the function it performs. It is in good condition.