Very nice and interesting finds but I hate to bring bad news but that shell could still be live because it still has its fuse in it and it can still be very dangerous and black powder can be very unstable in the condition its in...
SH...
I don't think I'd turn the "screw-driver" slot to try and open it to remove any explosives if I were you.
Quite the contrary... I'd build a glass case for it and display it out in the middle of a field... and anyone that wanted to see it should be made to fill out a "not responsible" form before taking a walk out to see it.
Be careful there. I do have some experiance with that kind of stuff. It is pretty cool until it blows your hand off.
Sorry about the doom & gloom. just my 2 cents
Nice finds all the same.
If it were me finding it I would have taken a photo, changed my pants and called the police on my way to church.