First off, great find! Do you plan to clean it up with some electrolysis?
As far as safe, it looks like the fuse is not set in place which would leave me to believe the shell is empty of powder, or if it's not empty, the ground water and weather will sure have ruined it. You can take a pen light and look inside and look for residues or anything besides the empty cavity of iron. If anything is in there flush it with water until everything stops coming out. IF you call or contact any EOD/law enforcement group they will take it and blow it up.
I wouldn't have any issues trusting this shell as it looks in the photos, but I have also been around this stuff a long time. If you need help with the electrolysis, let me know. If you're referring to Culpepper VA, I am not far out.