TreeDimensional

Sounds like you have your work cut out for you. Crown restoration is one of the hardest things for an arborist to do. I personally am conflicted at times as to whether to attempt a plan for fixing someone else's aggressive actions or to suggest a more site appropriate tree (bush). I have worked on previously topped American Elms before and it is pernickety work, and more often than not, you are still left with a tree that will NEVER represent or be as gracious as it's non-topped cousins.

I believe John Dee has offered a good advice as to the tolerance of this species to severe pruning. The other thing to consider is the climate and surroundings of this particular tree. The owner also has to be made aware that IF it is going to be a small tree rather than a bush, repeated visits from you will be required often, probably annually.

I don't think a picture is needed, most of us have seen wacked trees before, I shake my head every time I see one, and frankly, I am getting a SORE neck.