I was given a set of '68/'69 Road Runner (I checked with a pic on the net and found out they were not Charger tips like I had originally posted but actually Road Runner tips)tips by a friend to even up a debt. He states they are NOS tips. He has had them for as long as I've known him (about 18 years)so I have every reason to believe him since he has a nice stash of NOS parts at home.
How can I tell if they are NOS or a repro item?
They both have a small hole on the bottom of the tip at the back where it meets the pipe. I couldn't see a part number(but maybe i don't know where to look).

I don't want to list them incorrectly if I do decide sell them.

thanks
Al.