OV-25 Remote Ballast - Circa. 1960
This is my repainted Westinghouse OV-25 luminaire. This cobrahead is intended for a remote-mount ballast, thus the back half is cut short. This is intended for a 400W mercury vapor lamp. I currently do not have a ballast for this, so I run incandescent lamps in it when I want to light it up. This came from Seekonk Speedway in southeastern Massachusetts. This was the first street light I've ever owned, given to me as a Christmas present when I was in elementary school.
OV-10IB Integral Ballast - Early 1960s
This is a Narragansett Electric fixture replaced with a HPS light and given to me by a friend in 2011, who's friend works for National Grid. This is a 175W MV, 120V unit. This is one of my most prized collection pieces, as it is a very rare light outside of Rhode Island, though if you know where to look you can still find many of them still in service after nearly 60s years of dusk-to-dawn service. It's fixtures like these that question the integrity of newer LEDs on the market. 
MO-10 - Early 1960s
This is a 175W MV 120V open-bottom mercury vapor luminaire from Taunton, Massachusetts. This was removed during Taunton's changeover to LED.
RMA-10 NEMA Head - 1968
This is my repainted Westinghouse RMA-10 NEMA head. This is 100W MV, 120V and came out of Baltimore, Maryland. This was made in November 1968.
Viscount - 1971
This is a particularly interesting light I got in December 2017 from a fellow enthusiast out of northern Massachusetts. This is a 100W MV unit from June 1971. It is essentially a less utilitarian version of the RMA-10 featured directly above. Further, the refractor is made up of four separate pieces that interlock and stay in place courtesy of a spring that stretches around the bottom. Around the top is a wire with screw eyelets that attaches the refractor to the reflector, a flat piece of sheet metal, which is in turn screwed to the cast housing via three screws. Inside the fixture is a very unique lamp socket that doubles as a terminal block for the line connections. The slipfitter is also very unique. Turning the screw in the center of the rectangular piece of metal moves the slipfitter up or down inside the light, which allows the light to tilt up or down. This light only accepts 1-1/4" nominal pipe arms. This light was originally painted a baby blue color but the paint has worn completely off except for under the photocell receptacle (which is how I discovered the original paint color). I have no plans to repaint it but if that changes, I'm likely going to use silver paint unless I need a specific color for a specific application.
OV-15 "Silverliner" - 1971
This is my 100W MV Westinghouse OV-15 from October 1971. Has a 240V ballast with a 120V PC socket. I obtained this from a fellow enthusiast in December 2017.
OV-15 "Silverliner" - 1976
This is my 175W MV Westinghouse OV-15 from March 1976. Has a 240V ballast with a 120V PC receptacle. I got this in 2016 from another collector.
OV-15 - 1979
This is the later generation OV-15, which has a completely redesigned boxy housing. Many lighting enthusiasts dislike this version of the OV-15 because it's so drastically different from the classic round-bodied "silverliner" OV-15. However, I like both generations equally. As far as popularity in numbers, this version was far less popular in Rhode Island than the classic OV-15s. These boxy OV-15s were used sparsely in 250W HPS by RIDOT in the 80s. This particular model was an eBay score. This one had a 208V 200W HPS ballast and had no photocontrol receptacle. I added a PC receptacle and replaced the ballast and mogul lamp socket with 85W induction gear I've had for awhile. 
OV-15TD Tudor - 1980
This is a rather rare light, both because it's a Tudor version of the OV-15 and because it has full cut-off optics. This particular glass is frosted with miniature cube prisms rather than being just clear tempered glass, making for a smoother light pattern on the ground and less glare when looking at the light. This was made in September 1980 and is 150W HPS, 120V. This light was in rough shape after being in service near the coastline in the Boston area, so it was completely refurbished upon entering my possession. Now it looks too good to ever go back outside again!
OV-15 - Circa. 1980
This was obtained through another collector in December 2017. This is 100W MV, 120V. This particular unit had an OEM plastic refractor instead of a glass refractor. Starting in the late 70s manufacturers started offering acrylic refractors standard for HPS luminaires 150W and less and mercury vapor units 175W and less rather than glass refractors, which were always standard before that. This light also sports a NEMA wattage label, which started appearing on street lights in the mid-late 1970s.