1975 S Eisenhower Variety 1 Question

I am not by any means an expert on the Eisenhower dollar but a couple of weeks ago I had purchased a group of coins from a dealer that I have done business with before. Without checking my album I had agreed to purchase the reference coin, but when I received the coin it was a 1776 - 1976 S in the envelope that was clearly marked as a '75S Variety 1.

So I am confused about the this coin. Suffice it to say it is a fine looking coin and I am not about to complain because one can always use duplicates at a later point.

My question now is was there a coin that minted 1776 - 1976 that is or was cataloged as described? If so how would one determine it.

The only reason that I'm asking such a question is that there is a Jefferson coined in 1954 (?) with the reverse of 1955 that I asked about a couple weeks ago and it was determined that there was such a recognized variety. So I guess that I'm back asking about another variety.

Just to be clear about this, I don't feel like I was mislead because if it turns out that this is a mistake, I have no intention of returning what is a beautiful coin that can be used for barter purposes at a later time. I do hope that someone can help me with my quandry.