I opened the SVG in inkscape and discovered that the boxes are invisible until I changed the view from Normal to Outline, a handy feature of the program. From there, my discovery is that the grouping has been performed multiple times on objects that should have required only one level. I lost track of the number of times I selected the one object (all of the image), hit un-group and still had a single group of everything. Eventually, it broke up to three groups, but the individual components of each group had at least double level grouping, equally unnecessary.
Is it possible to upload/attach the CDR file which I can examine in Corel Draw and report back?
In additional attempts, I was able to un-group to six or seven levels (lost count) that ensured all components were separated. Clearing the selection, I then selected one invisible box and then used Edit, Select Same, Object type, which picked all the invisible boxes. Delete key and all is good with the world.
There’s an item that looks like an old-style phone handset that shows in the View, Outline mode, but not in normal and would probably end up in the cut. It also appears to be a good idea to weld or union the shapes once cleaned up. This is left as an exercise to the reader.