I dont think are specific “Shelby” valve covers in 1969?
Im not sure if the small block covers have internal numbers, but I can check.
A theory has been put forth by Special Ed that the 69 BB snake valve covers were meant for the GT500. I think it is very logical theory even if coming from a very illogical guy.
Every other year Shelby had special valve covers. In the end the standard CJ finned aluminum valve cover was used. The SB cobra valve cover doesn't have special numbers and the assemblyline type has to be identified by the visual characteristics .There were a lot of different evolution varieties of the closed letter SB Cobra valve cover over the years after Shelby production ceased. The same style Cobra valve cover was used on mid 66-70 Shelby's.