I'm no expert in errors, but if I'd have to answer...it looks legit. You can see doubling in the date clearly even from the bottom picture if that's not FROM the picture..
I don't think so, but I could be wrong. Here is a picture of a 1958 DDO http://lincolncentresource.com/doubledies/1958ddo1.html
I think to solve this mystery we need some better pictures. I'm agreeing with Tyler if those pictures from his link are the correct 1958 DDO.
Absolutely is possible to have different varieties. I'm not seeing spread nor split serif's on this coin, though, so I'd say the only doubling you have here might be die deterioration doubling or strike doubling.