Reddit reviews Tandy Leather Leather 5 Zipper Top Stop Brass 10/pk

I have no idea what they are specifically or if there's a proper name/designation for them but looking at the picture I offer my best guesstimates as to what you could use as a solution


Clip rings: with these I figure maybe a small incision along the collar line that you stick them through so the clip "mouth" faces out (instead of the back part that's the V which could be hidden inside the coat or lining)

I know you said you didn't think it was a zipper but looking at the picture I think maybe you could use one? though you could take off the zipper slide
So just in case you go that way

In the world of zippers I also found these top pieces (which seem to be clips for the bottom/top of zippers to act as stoppers)
Size option A
Size option B These seem like you could get use out of them, they come in packs of 10 so buy a bunch and then I think you could clip them on tightly to the fabric)

Since all the things are silver you could I'm use just weather/paint them a bit to get the match to the brass/gold in the picture. Like I said I have no solid idea of what they are but best estimate as to how you could do it this is what I offer