An old 35mm camera with a hot shoe, available at a lot of junk stores for a dollar or so, is the foundation of this little project.
2mm phone plugs are used for the electrical connections.
I don't know what the 1/4" 20 nut is called.
Cut the plastic surrounding the hot shoe to about 1 3/8" wide, 1 1/8" deep and 1/2" high. Be careful not to rip the wires going to the hot shoe! Cut to about 1" and strip.
Carve a place for the female connector in one corner. Hot glue connector and nut in place. Solder wires, make sure center connector of hot shoe goes to the tip of phone plug. Use more hot glue to hold wires in place.
Use epoxy putty to encase it all, trim before epoxy hardens! Paint black.
Total time about one hour.
Total cost, less than $10.00.
Information on slave flash trigger used in picture on lower right: https://pbase.com/sinoline/pic_ii