I've cleaned them and done some research online (thank you Anonymous Silver Expert who left a comment on the post). Here's the picture of the cleaned coins, and more info about them. It looks like I didn't make a great deal after all, but I'm happy nonetheless.
- The Hong-Kong silver dollar from 1867 is also only 900 fine. Yet, you can find at $350. I don't believe that valuation much.
- Japanese Trade Meiji Dollar = 1 Yen from 1875-7. Being 900 fine, it's obviously less valuable than a real silver ounce coin. But should have some (not much) numismatic value.
- The Silver One Ounce with no date no nothing is actually called a Mercury Dime.
- Silver dollar from 1922, apparently not much more value than the silver content.