Possible pattern as the Mint frequently experimented with planchet variations during the Wheat cent era in general and during WWII in particular.
Other thin planchet small cents are called patterns and sell for thousands of dollars each, such as Judd-299, Judd-356B, and Judd-405.
A fascinating anomaly regardless of what it is. Extremely rare on Wheat cents and vastly undervalued.
Sure to be the centerpiece of almost and Lincoln cent collection. Impress your friends and even your mother-in-law.