[New photos] Need help assessing value of vintage piece

I recently found this lovely older Omega for sale. Caliber 354.
From what I know of vintage Omegas, I think this dates from early to mid-1960s.
It is gold and the crown is not original. The seller says that the dial face is original and not restored. To my eye it appears original but I am not an expert.
What do you all think a fair price range for this piece might be (without the gold band; it is much too small for my wrist)? The seller will source and install an Omega crown if I decide to purchase the watch.

Need photos of the back, movement and inside the case back to determine value. Or, you could check eBay's sold listings, if you know the reference number. If you don't, see my first sentence.

Posted photos of all of the above. Please let me know what you think.

Fantastic, thanks very much. Any ideas on where I might be able to source the correct crown for it? I appreciate your help. The seller seems to think that it being gold makes it very valuable. I'll see if he's open to offers.