I have the tag here 😊
Thanks
first be aware that there is a good chance that the box was blacked out from above with a sloppy big brush with black paint - covering most if not all of the marks. We can't, at this point prove that this was done on all San Jose 69 Mustangs
From other examples I've found a big (covering 90%-100%+) of the end press in plug
A blue mark on the main body of the steering box. Blue is similar to engine blue or slightly (very slightly) lighter. Looks possibly sprayed heavy. One location on other boxes with the same identification just above the casting/engineering numbers (C7xxxx) on the large section of the main body. Don't forget the red dyed mounting bolts
Given your application you would also have a yellow stripe on the pittman arm nearer to the steering box attachment point