Tom, I believe the 'tool' you have is a work stand that held frames for repair. If so you are missing the piece that would go into the 1" hole, turn 90 degrees and then attatch to the frame . It held the frame with an expander that slipped into the seat tube. Does the piece have a number 479 on the casting? Also is it gold color and about 11" tall? A picture would help.
Peter Weigle
Lyme, Ct.