1951 D penny O damaged or mint error? photos included.

[mczark]

I have this 1951 D cent with the O in One being damaged. The area around the damage has the same patina as the rest of the coin. I'm wondering if this was an obstruction when struck or is this just old damage. The D is really thick but I don't think it is S D error.

[lex-talon · Accepted solution]

It looks to be old damage to me. Maybe a coin dealer can come along and verify it.