Being finished is a nebulous concept. . . as long as oil is wet, it can be changed and manipulated. Come to think of it, when it is dry, it can be painted over and changed! So how do I know when I am finished? Sometimes, it looks good. Sometimes there is a looming deadline. Sometimes, every new stroke is a mistake. Sometimes, there are other pieces needing to be worked on.
By the way, Paula, it is too wet to sign, varnish or put a wire on the back. Wait, no wire, it will sit on an easel! (gotta go floss the oil paint out of my teeth now. . . )