Update: my dealer had a change of heart. Actually, the owner got involved and he obviously understands the value of going the extra mile with customer service. Tech made a visit to my slip and, in 10 minutes, solved the issue by adding antifreeze fluid into the transducer. Transducer and cup were found firmly secured.
It was quite interesting to watch the 6'4" (guessing here) tech reach the unit. He lay down diagonally across the engine, facing forward, with his head to starboard and feet to port. Then, burying his head as far into the space as possible, reached down with his right arm to unscrew the protective piece of starboard (two screws), followed by removing the transducer from the cup and adding fluid with a long funnel. He said it was down by about half, just enough to allow air below the transducer. Everything was then buttoned up. Depth gauge sprung immediately to life afterwards. I wonder if I could have done it? I'm working on lengthening my arms and shrinking my belly. 😉
Anyway, happy ending and kudos to my dealer. Hope this will last a while.