This is not likely to be a mint error, I can't see how that would come about, it looks suspicious. You could pay to have it certified but I can't advise that in good conscience, as they are likely to agree it was altered. I agree it's somewhat convincing. But I'm not convinced.
DISCLAIMER (The fine print): We have answered your question about this coin despise the fact that it may not have met the qualifications for our complementary appraisals as explained in our FAQs. We ask collectors, before submitting queries, that they first consult our posted tutorials and prior posted questions and answers. We are up front that our specialties are classic and rare coins, and ask people not to submit images of damaged coins and modern minor varieties. We hope we were still able to help!
