Posted 6/15/2022 14:35 (#9706744 - in reply to #9706723) Subject: RE: Is this tool box
West Chazy, New York
The mount attaches to the frame rail and has a tongue that goes through the slot at the bottom of the box. A hairpin keeps it in place and allows you to take the box off or put it back on. I know they were used on 30 series and probably others.