Good evening, strummer.
3d. answer is a Celtic alphabet used in insciptions; take abbreviation for "0ld" (1), plus synonym for a school of whales (3) not lambs, even though they're partially gambolling!
14d yes, daily = char, and prefix for "three" is ter - think tercentenary.
Like you, can't understand wordplay for 19c. - something to do with a peter being a safe?
Al Issner