65 Bulova Rubaiyat from me. Nice find on the ad and the watch.
Interesting that they were still using the name after so many years. Although the pics in the link show the ladies' version, I'm inclined to go with Rubaiyat, the variant unknown.
Although similar, the Watch does not match the supporting ad presented by Ruby Lane.
ad is Dated 1968 and shown below

Agree - it is not the Rubaiyat. That seller acually lifted that ad from myBulova.com. What I am beginning to lean toward on this one is the "Diamond Excellency". We don't have an advert but it fit's the bill. I didn't realize that the bezel was diamond circled, I thought it was engraved.
all advertised 'DIAMOND EXCELLENCY's have a Diamond Dial, subject does not.
Am I missing something? The OP says the bezel is indeed diamonds.
Reverend,
There are no Diamonds on the Dial, it is the Bezel which is set in Diamonds.
I'm still at Unknown.
Bob says it's the Rubaiyat, did everyone get the memo?