Any thoughts on what these symbols or writing may be ? Found on my farm in McDowell County Treasure Valley where I have found European pottery & stoneware in the past ?

The one on the bottom right, those almost look like shamrocks on the bottom
of that plate shard. Irish?

I got your crock, Buckshot!
Back when I was in the archaeology lab I used to enjoy trying to identify historic ceramic sherds. I mean atleast they'd sign it!

All those cracks on the surface of the piece on the left is a tell tale sign of a stoneware called Ironstone. Ironstone is a stoneware that was used widely from 1813 - 1900 and on into the 1900's by some. Ironstone was known for that cracked surface which is called, "crazing".
Don't have a positive ID on your piece there, but I am guessing it was made in Great Britain by the Minton company, Europes' leading ceramic factory from 1793 - 1968, when they merged with another company. I'm guessing, but am not sure, that this piece is from a series called, "Amherst Japan Stone Ware" circa 1850. Here's a link to picture of what I am thinking is your mark.
https://www.worthpoint.com/marks/ceramics/mark-76043_scroll-amherst-japan

But I'm pretty confident the piece on the right was made by "Goodwin Bros", Liverpool, Ohio, 1844 - 1898. They were also making Ironstone, but in 1875 when the father died, the Bros developed their own Ironstone ceramic using local clay and called it "Pearl White", and I think that is what you found a piece of, 1875-1900.
Here's a link that shows the whole mark. Scroll down to Goodwin Bros.
https://www.themuseumofceramics.com/gallery6

Thanks Joe, looks like you nailed for sure it on the 2nd piece Goodwin.
I agree with what IDLassie said, you're a wealth of knowledge.