Way cool spoons for sure. Point one is with out markings to prove the date then we are talking hear say on the date. Which I would be surprised by these being that old for sure personnally. 17c would me pre colonial in age, making them 400+ years old, most items that are truely that old are in Musuems and high end private colloctors diplays. But again anything is possible, to prove it to a potiental buyer will be another issue. The second point is they do not appear to be functionally spoons, and made more decorative in nature, all the fillagre and metal work to make it well, lets just say I would hate to be the servant that would have to wash such a item. Which during that age not much items was made for decorative purposes, unless you was a high end Royal person. I would not doubt they were brought back in the mid century era, but if I saw them in a shop, I would say Early to mid century tourist items. I am not sure I could put a good value on the item personally, but maybe some else can help a bit more, my guess would be low for sure. But this is out of my expertise, but I thought I would just add my thoughts. Thanks for posting.