Guess you've been looking pictures on the internet or in magazines and guess this is not what you found on your specific car. In your particular case I would guess that you were looking at pictures of Dearborn car (as most restored 70's seem to be) which don't translate/relate to your San Jose car. Found by having to go back and look through your prior posts. Might want to add that to your signature
Have seen these many times on restored car we're it appears they copied other cars they saw like you have and often owners are surprised later when someone ask later if they are original to the car or even that they are not correct. Typically we want to remind owners that the time to focus (if ever depending on how you plan to use the car) there are allot more important details that one should make sure are all correct before worrying about marks.
As a side note - only talked to one San Jose worker that recalls putting an "X" on cars in 69-70 and he was the shock installer and he stated he might put one or two on cars all day long or maybe none. Of course the car he might have put one on that day could have been a Cougar and the mark was not applied to the hood latch support