Related Clues:
- Helmets, 26-Down and such
- Had eager spin bowler?
- Skull with key element lacking on top
- Radioactive material initially replaced in hard case
- Key radioactive material abandoned by university head?
- Pit's mechanism for hoisting lids
- Hats, helmets etc.
- Hats etc are found in shrubbery by middle of park
- Hats, helmets, etc.
- Mortarboard, especially?
- It's repeatedly exemplified in Crown Derby
- Hats, helmets, etc
- Head copper guarding princess's millions
- Skull of a vertebrate
- Braincase