Thanks for sharing the link to the pictures. Very interesting as I've always heard of their presence within a browstone building in Brooklyn.
In the pictures, I noted the following:
* The lathe appears to be housed in a red box with the glass window. I suspect they are using a CNC machine to cut all of the mahogany cups as well as the inserts for the PS-1000, and PS-500.
* The time clock on the wall for punching in / punching out during the start and end of work only had 5 time cards in the slots. Does Mr. Grado use a card? My guess is yes. This operation is "old school" pretty much all of the way with the exception of the parts (headbands, gimbals, etc.)
I saw the time clock as well and had a quiet chuckle. I haven't seen one of those since my first job at a very old-fashioned supermarket/dry goods store in rural South Africa...that was almost 20 years ago now, and it was regarded as a working antique.
The CNC for the cups and inserts makes sense, especially the inserts. Everyone I have talked to about inserts mentions how painful it is to turn them by hand.
I am still staring at the 5th picture and wondering if that's where the drivers are either made or "doped".