Anyone help on this 1956 partial overprint

Spahnfan

I have this 1956 Topps team card. The 1955 has not been completely blacked out so you can see the year. Obviously it is not as sharp and clear as a normal dated card. So, what do I have? You can see the date, so is it a dated card? It has been overprinted in black, but not dark enough to cover the year. Is it a partial overprint? Or since it has been overprinted, is it just a Team Left variety? There is no evidence of tampering that I can see. The gloss is normal and does not look altered in any way. Anyone with experience with this before?