Need Help With Grandpa's Vintage Seamaster

I need help identifying my grandpa's chronograph seamaster that I acquired from his estate. It still runs beautifully. However, since I am female it is a little too big for my wrist and I haven't decided if I am going to keep it for myself or sell it. I love vintage watches and own quite a few. I have also been able to clean up the ones I own myself, but with my grandpa's omega I don't want to take any chances. The questions I have are: (1) What model and year is this? I have been told he got it in the 1960's. (2) If I decide to sell it, is it better to sell it as is or should I get it cleaned and have the crystal replaced due to the scratches? and (3) If it should be cleaned whether I sell it, or keep it for myself, does anyone know of a reputable vintage watch repairman located in or near the City of Huntington Beach, CA. Thank you for any imput.