Larry - Here's a zoomed in shot of the bracket on edge that shows what looks to be 2 pieces. The long ribbed piece that bolts to the frame at the bottom and is riveted to the top area of the inner fender panel is backed by the 2nd piece and seems to be welded to the main ribbed bracket and perhaps welded to the lower shelf of the panel. You can see the remnant of that rear bracket still attached to the lower shelf of your panel as is the remnant of the long ribbed piece at the top of the panel in your posted picture.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)