r/VintageClothing

Hi -- I've posted here before. I do the vintage section of a charity thrift shop in L.A. We got in this dress, which I think is late 50s/early 60s. Metal back zipper, tag attached to zipper cut off, lace hem ribbon. But on the back (last photo) is this weird thing -- there are two black cords attached to the shoulder lining which are connected by this small metal doohickey -- like what you'd see on a sweatshirt or something to loosen or tighten the neck cord. I've never seen anything like this before. The problem is, it pulls the lining out past the neckline and ruins the line of the sleeves. Does anyone know what this is?

I want to know if anyone with experience on vintage pieces like this has an idea of a pricing. I will copy paste an AI paragraph as I dont know much about it myself.
Item Overview & Provenance:
Era: Late 1980s (circa 1986–1989). 
Origin: Made in France at the historic Ventex factory in Troyes, France. 
Tags:
Original 4-country flag neck tag (France, Germany, UK, Italy) with Trefoil, tagged Size M. 
Crisp internal side-seam tag explicitly reading ⁠PRODUCTION VENTEX⁠. 
Fabric Blend: 80% Cotton / 20% Acrylic (classic heavyweight French loopback fleece). 
Theme: Dedicated tribute to Compagnie Générale Aéropostale (the legendary French transatlantic airmail service flown by Antoine de Saint-Exupéry along the France-to-South America air route). 

As context the closest thing I saw was this item sold on ebay, which went for over 600 usd

A few years ago I bought this winter coat on Vinted to an Italian, it costed me 5€ and I still am amazed to how it cheap it was for this quality level. I still have no idea how to find more of this brand, or let's say I'm just curious about it. Looks French, obviously, even though I bought it from an Italian woman, maybe she was selling it from her late grandfather, because Google Lens tells me it looks from the 60s. It also says it's a heavy wool herringbone coat, the interior label says "Partner Paris" and features an embroidered crest showing two medieval figures with swords, in green and copper. It looks like a thick wool drapery so it might be a high-end coat. I never felt cold with it, that I can assure. Do you, fellow vintage clothing enjoyers, have an idea about that brand and this coat? Thanks a lot for your kind help.