When a 66 Mustang body was built at San Jose with the intent of it becoming a 66 Shelby part of the package was an export brace. A one piece brace that bolted to each shock tower (under the forward upper shock mount) at to the top of the cowl where the firewall and cowl are welded together. At this location a support brace was welded over the cowl metal and then the edges (and often more) were sealed finished with a brush or rag. In some of the pictures below you can see along the edge of the support the welds along the top and at the ends though the thinner sealer application
The same bracket/support was also installed on most of the 1966 Mustangs that were ordered as as export cars.
The export design and details are covered in one or more other threads but the bracket/support has not so I thought I would post some pictures of some typical examples from the Jan - Mar 1966 period.