I promised to post the identity of the mystery box (post on 4/9) after I had two guesses. I just got a final guess by phone from another family member who hasn't yet figured out how to use the "comments" (sorry, Dad!). And the winner is... my dad, who correctly guessed that the item in question is a table saw. Munchkin had just "replaced the blade."
Thanks for playing. Stay tuned for the next episode of "It's a mystery!"