Lincoln Memorial penny shop

Product Name: Lincoln Memorial penny shop
I have a one of a kind 1971-D Memorial penny with a rare error in the date. 1971 /71 has a tilted 1. Or is this a 1974-D? 74 shop wth weak 4. Look at the pictures closely if you can enlarge your picture you will see a shadow of a 4. I've researched the error and could not find anything like it. I checked Wexlers coin errors and other sites. It's nowhere to be found. The coin is as one of a kind and in fine condition once again check the pictures. I'm asking a fare price but open to offers. Aso there is a weak strike on the FG on the reverse.