Regatta 23
Finding a linebook match for the Bulova Regatta 23. Thinking this example is the "H" variant due to the dial being gold tone rather than silver tone, which I think is the difference here.
1963 Bulova Regatt 23 "H"

I'm not sure if the "H" dial is gold or silver or if the only difference between these two is the band. "H" variant works for me.
It seems that the only difference is the band, i might be slightly more inclined to leave the variant off this on? 1963 Bulova 23
I guess it depends on the photo and if the coloring is correct.
This looks lighter and as such the "G" variant. Subjct looks darker, but again could just be the photo.
Bulova 1963 Regatta 23 | myBulova.com

Removing the dial color, if it even exists, then I agree that the bracelet might be the determining factor, in which case a generic Regatta 23 is appropriate as we cannot differentiate between the G or H variants.
I have to agree with Stephen on this one. With the absence of an original band as depicted in the linebook, it's impossible to assign a variant based on the info we have to work with.
1963 Regatta 23 -(generic)
The photos of both watches in the linebooks are in the same photo side by side, and the lighting would impact all the watches on the page. If in fact the subject watch photo is showing a gold, not silver dial, I think we have a case for the variant. If ralwan can confirm the color of the dial is actually gold not bright silver, it would be clear to me that the watch dials are different colors. I am not sold that the bracelet style would change the variant from one bracelet to another. Leather to Bracelet yes but bracelet to bracelet seems a stretch. If the dial color is confirmed, then we have two different dial colors and what appears to be a linebook photo that supports the variant designations. I did check ads on Newspapers.com and could not find any that mentioned dial color.
In reply to The photos of both watches… by JimDon5822
The dial color is definitely gold. I have two of these watches and they both have gold dials. The other one's dial is slightly damaged.
1963 Bulova Regatt 23 (generic) gets my vote.