Brian, Your seat riser may have been damaged by the adjuster ripping through the support and/or the seat adjuster and frame hammering on the riser with the bolts loosened up. Mason's picture shows what it's supposed to look like. I can see the remnants of the mounting holes in your picture.
Mine were similarly damaged, only worse. I rebuilt them by welding replacement sheet metal in. An other 'bolter helpfully sent me pics of the dimensions to locate the seat adjuster mounting holes. The holes in the rear should be located to align with the seat adjuster when it's aligned at right angles to the front of the seat riser. Check the distance between them using the mounting holes at the rear of the seat frame.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
