First off, it is unwise to attempt to authenticate a 1943-P "Copper" Lincoln Cent based on pics alone. A close-up and personal examination is necessary as well as knowing the weight of the coin. While I don't see anything really amiss with the Date due to subtle differences in each Obverse Die used to mint the 1943-P Lincoln Cents (i.e. wear, repairs in the way of grinding and polishing as well as Die Deterioration), these are still always suspect. You could examine 100 of the 1943-P "Zinc coated Steel" Lincoln Cents and out of those, you would probably find at least 10 different variations of the "3" in the Date due to one or more of the conditions noted in the brackets in the previous sentence. The best way to know for sure, is to have the Seller get the coin certified and graded. However, since they are selling it raw and you are purchasing it raw at probably a very low price, this would not fair well for you, as the Seller would more than likely raise the price significantly. It would be best to probably decline on the purchase and live with it, even if it does come out to be authentic because the chance that it is not authentic, are too high!
Frank