Those are some really nice early buckles - definitely mid-1600s thru early 1700s. I've found some like the smaller one shown in your first few pics with the stud chape. But the larger one I haven't specifically seen, especially with those markings etched all over the frame. For a great reference on early buckles you download the following:
http://www.reenactor.ru/ARH/PDF/Whitehead.pdf
I also have a book on 17th century spoons that has a large number of maker's marks listed. But yours is not shown. But the majority of these spoons date between 1650 and 1700 which is in line with your other recoveries. If you want a copy of this book you can download a free pdf at the following:
Old Base Metal Spoons - Frederick George Hilton Price - Google Books
Love to see you post the coins, buttons and other artifacts that were dug at this site. And I hope you pursue locating the trash pits too as that could be a very fun and lucrative find. Good luck!