Well, dang! I forgot all about this thread and in the meantime...and a lot of meantime, at that...the project is done. Here's a sampling of progress pics taken over several months of weekend and evening work. All photos are clickable, by the way.
They picked it up a couple of weekends back and now it looks right at home. Not shown in the photos below, is the glass cover...since it wouldn't photograph well...and he likes the way it looks uncovered. The trim piece is removable, allowing the base to drop in, and the glass cover then fits within the trim. I had made MDF templates of the base and cover to check fit during construction and left some wiggle room for good measure. But still, I had small a nagging dread that they'd get it home and it wouldn't work out. But they report that it's a perfect fit and they're delighted with it. Relief.