Awesome to see this beauty still working!

No kidding. You should see the night scenes I did a couple of years back or so.
https://www.lighting-gallery.net/gallery/displayimage.php?pos=-113014
https://www.lighting-gallery.net/gallery/displayimage.php?pos=-113605
https://www.lighting-gallery.net/gallery/displayimage.php?pos=-114486
Just to name a few.

David are there still many mercury vapor streetlights even left up there? Westinghouse Silverliners, G.E., Line Material, Pemco?

There are some left on Boylston Street, The Fenway, Park Drive, some on Centre Street in the West Roxbury area, Old Colony Avenue in South Boston, and Arborway in Jamaica Plain.

Cool! In my town LCEC is still only replacing low wattage streetlights with LED, (100 and 150 watt HPS). They're still maintaining and replacing 250 and 400 watt HPS. FPL is still all HPS, maybe not everywhere though. I still see plenty of new installations of HPS including several massive cobrahead and high mast installations on I-75.

There's 2 GE M-1000's in Harrison Township, PA and 3 GE M-1000's in New Kensington, PA that are still in service, but most of the other mercury vapor street lights in those towns were upgraded to LED's last year.

Lamp looks very dim.

Probably 'cause the bulb is nearing the end of its average rated life of 24,000 hours.

Last incarnation of the M-1000 before GE discontinued it in 1987. So this fixture looks to be somewhere in the mid 1980s.

Yeah, I think the last generation came out in 1979? I know M1000s made in 1977 still had the older door design. Seen them with blue tags.

Yeah I've seen old style door M-1000s with NEMA tags at Garden City in Cranston. They were retrofitted to 320W PSMH and removed a few years ago when they went LED. I was able to save a pair of M-400A2s (also converted to 320W PSMH; from 400w HPS) but wasn't able to beat the scrappers to the M-1000s and other lights.

In my collection, I actually have a '71 M-1000 with a replacement step door (neoprene gasket). Originally a 1000 watt MV, I converted it to 1000 watt HPS and got the shallow glass for it.