I am just wondering if there were any decorative mercury vapor fixtures that were designed with A23 mercury vapor lamps in mind where the bare lamp can be seen to give an incandescent look to the fixture such as period street lights?

A lot of indoor recessed downlights in the 70s were designed for a 100w A23 MV in place of a 150w incandescent lamp. They were also common enough in post tops to the point where a picture of a A23 mercury lamp in a post top was on the package of older Philips lamps.

BTW if you want to look a pictures of old vintage HID lights, there's a lot of old literature here with catalogues from the 60s, 70s, 80s, and 90s of old HID lights.

 Cool link ! That will take me DAYS to look at everything there !!