Wasn't relamped all that long ago either since that photocell has a green window. Sun-Tech didn't start the green windows until 2011 or 2012. Before that they used a green insert behind a clear window.
There's only a few streets in Boston that haven't transitioned to LED yet. Turtle Pond Parkway, Dedham Parkway, Eneking Parkway (Hyde Park), Soldiers Field Road (Allston), Fenway, Agassiz Road (Fenway), Arborway (Jamaica Plain), and Centre Street (Roslindale).
That's a later model OV-15. I have one just like it. These have the standard Westie 4 bolt slipfitters rather than the two bolt and external angle adjustment of the earlier versions.
Those OV-15s with the external bolts are pretty early on. By the 70s they'd done away with those. I have a 175W 240V one from 1976 or 1977. Very LOUD ballast for a simple choke! Even after making sure all the bolts are snug.