I've never really tried looking for errors, just have always collected by dates, designs, etc. So I have probably $100 face value of coins that I've never checked for errors. I've been looking thorough some of my coins and have found some possible errors. For now I'm just posting this one but I'll add more later. This coin is missing a letter, So is it an error?
Your 1969 has a slight Misaligned Die Strike on the Obverse. The issue on the back is common. When the blank planchet is struck the image of Lincoln on the Obverse actually affects the area in question on the reverse. Since Lincoln's bust is a bit raised above the field it sort of weakens the area on the opposite side. It is like a weak strike which doesn't allow the few letters not to form properly. Also, the reverse die could have been a bit over abraded which caused a slight Floating Roof effect and the weak FG strike on the right side of the memorial building. But those issues are not considered errors.