Evasive Half Penny ?

Certainly does not look like a Regal issue - the weight would confirm it. It looks to be a contemporary counterfeit or non-Regal coin rather than an evasion - evasions have some obvious element of the design that differs from the original, such as a different portrait or wording. Evasions are much more collectable than the non-Regal coins and, as yours is in pretty poor order, I would not expect it to make more than a pound or two.

Contemporary counterfeit, common.