Seems that a good percentage of people that own 69 or 70 Mustangs with a F code (302 V8) think they have a Boss 302.
The VIN is likely going to be the quickest way to educate if they are open to listening. 5th digit in the VIN would be a "G" if it were a real Boss 302. But to your original question carlite65 is correct according, as far as I've seen or heard factory records.
Guessing by the quote this is all memory and recall so take that for what it is worth