Ed, I have attached a pic of the LH back head and what is left of it, I am pretty sure its a yellow paint mark below the serial number, which I have block part of, it is a very low number first week of production I do believe being Sept 4, 1969. Sorry I do not have any good pictures of the paint around the starter or starter cable area, I took those picture back in 2007 with a cheap camera while disassembling the car for restoration. I initially only took the pictures to review for reassembly NOT to document markings and other concours information.
The engine had many yellow markings on it especially on the crank shaft, I was amazed at the markings on it when I opened up the motor.
Also the LH valve cover has a OK with NO hyphen and the emissions stick is a 390 and not 428 which are both original factory applied.
The back axle also had many markings on it, the interesting ones where the white and pink ones on the axle shafts where they are inside the housing and also there where markings on the inside of the bowl of the housing itself.