VINTAGE LUDWIG CHICAGO SPUR-LOK HI HAT CYMBAL STAND DRUM 1960S 1970S - (Galesburg in Kalamazoo, MI

This is a vintage Ludwig Hi Hat Cymbal Stand. My son no longer plays the drums, so I am selling the last of his accessories. This stand is very solid. It works well. The pedal moves freely. It adjusts to heights well. I cannot figure out how the top secures into place. The top is threaded, but I cannot figure out what it screws into. Feel free to e