I’m not seeing a lot of Indian artifacts but you definitely have post contact stuff… wether it’s 1500 or 1900 I cant say but i think you’re in the right mindset as far as being curious and enjoying the hunt and trying to decipher what you find, sometimes it can feel like people are bursting your bubble but I would assume most are rooting for you to keep going and post back with a true stunner of a find… hope your dad was right and there is something special there, you just haven’t found the key artifacts yet. Personally I keep nails and things just in case other things come along, say you find some Spanish coins and a bit of chain mail among the nails and buckle bits… all of a sudden those square nails and scraps become a lot more interesting