1925-S California Commemorative Half Dollar Diamond Jubilee Grade Please

Well, Almost looks like it was dipped then put in a cardboard holder and re-toned. Are those scratches under "PLURIBUS" or die polish lines? Hmmmm. I'll say MS-63. If your coin, you may want to try and remove the green spot on the obverse @ 4:00. Toothpick should work.

Your photographs ... for me ... are sufficient to determine authenticity and to develop a general idea on grade and surface condition.

For my perspective ... with significant experience in this series -

Your example is authentic (good for you, plenty of counterfeit of this coin out there) and likely MS with questionable surfaces likely deviating from original.

Surface condition clues for me are the unnatural re-toning noted above, the interrupted nature of that toning as seen on the obverse as well as the residue of wiping/cleaning as seen as surface scratches on the reverse.

My opinion is authentic MS-Details (Altered Surfaces)

Still ... its a lovely example of our collective USA coinage history and I thank you for sharing the coin with us.