Didn't get very far with this so went to 225 for enlightenment. 12a was
"It’s vulgarity to mind your old ship "
Answer was given as EARTHINESS EAR (mind) + THINE (your, old) + SS (ship)
Someone queried ear =mind and a commentor said "The dreaded Chambers gives EAR and MIND as attention."
I can't think of a sentence where you could use ear and mind interchangeably. Any offers , please?