After PR #248 is implemented, I think the Edition and Work  display page would need to be changed so that it appears more in line with the EditionGroup or Publisher display pages.

Mainly, instead of having the works/editions appear under relationships, add a section to display all the works contained in the edition (and vice-versa) and hide them from the "Relationships" section.

That way, the new "Add Work" / "Add Edition" buttons will make more sense and be more consistent across pages.

I attached a mockup to this issue for clarity