I am convinced that the apparent doubling in the date is due to die wear, but am not so sure about the mint mark. It actually looks like the bottom serif is tripled. There are a couple of robust die scratches that could serve as markers and I will include photos of those. I would appreciate thoughts on whether this looks like an RPM.
http://www.coppercoins.com/lincoln/diestate.php?date=1943&die_id=1943s1mm008&die_state=lds Not sure if thats a nic on your S or not, but this may be close...
I think what you're seeing on the bottom part of the S is from the same thing that's around the 9, from a worn die. However the photo Abe linked to might be what your coin actually is. The mintmark to the date position looks like a real close match. If you look at the pic in the link, where the arrow is pointing, is where the actual doubling is. It looks very similar to your coin.
I looked at coppercoins before posting. The problem is that the coin pictured in that link is listed as LDS, but it also says no die markers were found. I can't imagine anyone missing the markers that I imaged above.
