1979 S 109 576 000 € 1.00 € 1.02 € 1.31 € 1.27 € 1.68 22% 1979 S 3 677 175 € 4.95 6% Type 1 - Proof 1979 S € 32 1.6% Type 2 - Proof This is extracted from this page, https://en.numista.com/catalogue/pieces3548.html If you meant yours does not physically resemble these, http://varietyvista.com/14 SBA Dollars/San Francisco Mintmark Styles.htm it looks like yours took a hit in the middle, slightly changing its shape, a better image with less light bouncing off the subject would give members more chance to form an opinion
There was a Type 1 and a Type 2 Susan B. Anthony dollar in 1979, with the S being the difference. The filled S, like yours, was the Type 1. I'm sorry to say the Type 2s are more valuable.