if you were able to see the rope and chain,etc. then did you open them apart? or were they clearly visible when you looked inside...
Why, I never! Cut open clothes? That were not mine? I'm teasing.

Gius, I share your fascination with garment construction, but as you are a student of it, you probably feel more compelled than me to take things apart, to understand the technique. The 'coin' was definitely placed inside the fabric, as was the chain within sleeves and dress/skirt hems. However, there is also this chain I noticed on the inner (but exterior of the fabric) bodice of jackets, extending from one shoulder blade to the other. I don't think it was meant to be for hanging the jacket, so maybe it was to add or hold shape?
As for the rope, I feel like it was usually sewn within the garment, but not inside the fabric. When I say inside the fabric, keep in mind that most vintage clothes I've seen tend to have more than one layer of fabric; if it's a summer item, it will have a lining in the least. And sometimes I think heavier embellishment threads that could qualify as 'rope' or buttons, ruffles etc. have both decorative
and constructive uses (ie. they add to the visual aesthetic of the item but also inform its shape and structure).
and they are probably couture, no?
Well, you don't mean haute couture, right? I'm fuzzy on what decade onwards qualifies as vintage, but I feel like older garment techniques were much closer to couture standards than now. By standards, I mean they were upheld whether you were the simple neighborhood tailor or working for a major fashion house.
Perhaps the only notable difference was in the quality of threads (surprisingly $$$) and fabric available to you. My paternal grandmother was one of those 'simple' seamstresses and yet, when I look at her work, her precision, attention to detail, and mastery of very complex silhouettes is awe-inspiring.
Not that badly-made clothes didn't always exist. I have come across my fair share of junk, but I think the overall decline in a couture-like mindset is obvious is the late 60's, early 70's. For one thing, too much freaking polyester! But my mom has a few clothes from that time made by seamstresses/tailors, when it was still common practice to get clothes made from scratch for certain occasions. And the quality remains top-notch.