About the best information I can give you is that the Mopar part number for it was 3419796. The same part number was used 1972-'74; I didn't check earlier catalogs.
The '73 I had as a kid had a similar moulding, but I could've sworn mine was just held on with two-sided tape. I removed them shortly after I got the car. I figured the original owner added them--Trim-Brite sold that stuff in rolls--and never thought much more about it. I just dug out the original window sticker for that car and sho' 'nuff, they're called out on it: V5X VINYL BODY SIDE MOULDINGS, a $13.90 option. I really don't remember buffing or waxing around a line of mounting studs, but that was also 33 years ago too.
I'd suggest the usual suspects in terms of finding NOS (Brad's, Arizona, etc.), or maybe just save an eBay search for the part number. I think a lot of cars lost that moulding in a "restoration" since you don't seem to see many with it anymore. I tore mine off because I didn't care for the look.
While I realize it's far from ideal, you might want to look at aftermarket options that closely resemble the profile of the original pieces. I found
this place that sells a lot of styles/colors of body side mouldings; Trim-Brite is out of the game but I'd bet there are others. If you find something close, some very-careful, shallow drilling on the back of the moulding would make clearance for the studs. It might be good enough for the time being until the magic OEM part lands in your lap... it's just a thought.