Thanks for the warning and recommendations, guys.
Tim, perhaps there is a better sealing tape to use. I used the Scotch one inch wide Professional Grade #2228 Moisture Sealing Electrical Tape. It definitely is up to the job! Trouble is I have to razor knife the tape and reef on it hard to get the stuff to come off.
rickbb, I have used dark lithium grease for trailer hitches which works very well but it is a substance you don't want to get on your clothes! I have never heard of white lithium grease, especially in a spray form. What happens if you need to service or just tweak the antennas? You said the connectors can be undone easily - but are they really re-usable?
Ken