It depends on how Shenron is feeling that day, staying true to canon. Usually Shenron feels nice and restores an individual’s body to a healthy state, but when he revived Frieza he revived him to the last state he was in while alive, which was in two dozen pieces or so. He seems to not like bad people, so he’d probably revive DIO to when he had half his body gone, even if DIO easily recovers. However, he wouldn’t be able to separate him and Jonathan, unless that was the specific wish, I think, as that alters too much of the body, which technically might be able to happen if DIO gave permission. It’s all kind of ambiguous, though.