1976 rear upper wheel arch panel

[kcwis]

I got a panel from another vendor (triplus) that seems thin,and the lip doesn't match oem, oem is approx 1 inch, this panel 1/2 inch,also the lip shape does not look like it will match, anyone have recommendations? what brands have others used?  It's for a 76 gmc fleetside long bed passenger side.