From my phone it doesn't look like an s-works. Although maybe a repainted s-works? Weld does look odd compared to the others, it should be consistent with the others. Possible repair and then re-paint?
Specialized did make an alloy s-works, it was m5 tubing. Thats been resprayed. I had the epic marathon which was an amazing ride! Epics came with that brace on mediums and up
Plus the S-works had an adjustable brain fade which that doesn't seem to have.