These appear to be west elm circle cut out chairs. I don't think they in the online catalogue anymore, but I did a quick search and it looks like some sets are coming up for sale on other sites.

If you have long dinners, they are not particularly comfortable. I gave away a set years ago. Ok for quick meals.

Before replacing your curtains as this can be quite expensive for such a large window, if they are in good condition, add a band of extra fabric to the bottom in what ever suits you, your existing curtain track can then be moved up to the ceiling for good looking full length curtains without the large round eyelets, could save you a lot of money, I would look at replacing/removing the sheers cheers

Stunning! If you contact Vampt Vintage Design, they may be able to at least tell you the name of the design/er.. http://vamptvintagedesign.com/product-category/chairs Also, Matt Blatt does great, quality replicas and I saw similar, but not exactly the same design in their catalogue. https://www.mattblatt.com.au/?gclid=Cj0KCQiAvKzhBRC1ARIsANEXdgyCuVyOY4r63pTpsiA8bm2X7EE_jjvQuee_lVWLFi2vDkPQSK8Zf-MaAtyXEALw_wcB