Hi Dave,
Not a direct answer as I have an original rumble lid but I did buy the panel above it from Steves .
The curvature side to side is NOT the same .
Rumble lid is in original paint and is decent with a few dings .
Nothing to alter it's shape .
Difference is way beyond a bondo job .
Panel looks good with proper braces for legs .
No little reinforcements for side bolts though .
Definately does not match lid though .
May want to get a template from them to check this .