treemandan
Tree Freak
I might add that the lady is really fond on keeping this tree. I actually worked on this property 5 years ago when I worked for my last boss. He told the HO that the vines were OK and he's a certified arborist. I think he didn't want to get involve in the removal of vines.
So if she goes for somewhere around a G for the de-vine I think it would be worth doing the job. I also think the ivy comes off pretty well without to much bark damage but its still going to be a mess.
I don't beleive the ivy is hurting the tree that bad. One thing to consider is the bark will be getting sun it is not used to getting.