Looking GOOOOOD!

WOW!...thats a real rare one!

Nope...not rare.....it's common as gull's turd in my area and in many places I have visited like in Illinois, New York, NJ and others........the GE Form 175 remote ballast...on the other hand is the RARE one!

Very nice light, and yeah different places will have different lights that are common and rare, kind of like commonly seeing OV 25s and gumballs here and rarely seeing a GE M-250A2 here.

One reason why those aren't too rare is because they continued to produce those until 1965!

When did they start production of the 10s?

I love these things.

The OV 10 was a common sight on Chicago side streets (along with GE Form 175 and Revere Peahead and various Gumballs) before they were all replaced by the GE Crimefighter back in early 1968.

No clamshells here. Everythings cobraheads.

Last clamshell on a street that I knew of got removed in late '09
There's still a few left in parking lots..etc.

My recollection is that why there weren't as many OV 10s as with some other models is that most MVs I saw in the 50s through the 60s were higher output (400w) for commercial and industrial areas and large boulevards. Most residential neighborhoods seemed to prefer more natural incandescent light and they stayed that way until energy costs went through the roof and HPS became popular. Some areas with sensible electrical rates still have incandescent systems in residential areas. Google Street View some neighborhoods in Salt Lake City, for example.

In Frederick MD, there are a lot of clamshells (most of them are OV-10s and smaller Joslyn clamshells!) but almost all varities possible are found there. Most are retrofitted with series HPS ballasts and most also kept the series MV ballasts but with retrofit HPS lamps! There's a few that are still mercury vapor! The gumballs there used to be incandescent, but was recently retrofitted with series HPS ballasts!