A custom lampshade manufacturer in San Francisco requested measurements to ascertain safe distances between shade and bulb for a shade I ordered, and I sent them this photo ( It turned out that it wasn't right for my living room, and I gave it away--live and learn).
We bought the lamp at the Red Barn in Aromas, California, for ten or 15 dollars in 1970 without a shade.
I purchased a stained glass lampshade kit in North Beach for seventy five dollars, and soldered a fitting shade in my father-in-law's garage over two or three hot Salinas afternoons.
A divorce can make you do strange things, and in my case, I sold the shade at my yard sale for ten dollars.
I've long since settled on a black shade that suits me fine.