Cap with Embedded Nut for Moon Lamp

the new file has an integrated screw to fit the lamp top as shown

includes cap files for the regular sized moon and a smaller moon printed at 85% scale from this link: https://www.prusaprinters.org/prints/75909-remix-of-moon-lamp-for-the-prusa-mini-printer

I think it's supposed to be this socket type: "B&P Lamp Threaded Shell with Ring Phenolic Socket"

see following links for examples of images
https://www.amazon.com/s?k=b%26p+lamp+socket
https://www.amazon.com/s?k=b%26p+lamp+socket+nut
https://www.amazon.com/Lamp-Turn-Knob-Phenolic-Socket-Threaded/dp/B01M1LNGFO

"There is also a self designed M39x2.5 union nut. You propably will have to scale the nut up in X and Y by a few percent to make it fit." - from maciejb's link