Vintage Seamaster Day/Date Sparkle Dial ID & Advice

I'm looking for information on a Seamaster that I inherited from my uncle (lived and worked in Philadelphia and passed in '05).

From what I can tell so far it is late 60s, sparkle dial, day/date.
The watch is not working, I have had it in my jewelry drawer for years. The second hand is not attached but still under the crystal. Looks like the crown is not original. The band is marked stainless steel, USA-- gold colored on one side, stainless color on the other.

I am interested in selling it as is, I don't really want to put money into it.
Wondering what ID info I should have before selling and if I need to have it opened up.

Would love any id info, idea of value, advice.
Thank you!

Take the expandable bracelet off as it's not original to the watch. It should be an easy open for any watch shop or even do it yourself if able and take lots of photos. If you want to sell it just put it up on eBay starting at 99c and let the market set the value.