Possible Clues:

• Egg-shaped
• Fairly elliptic poet left unfinished by schoolchildren
• Order including usual number in eggbox, because that's what eggs are like
• Like eggs, half-a-dozen coated in old mould
• Not quite spherical
• Egg-shaped decoration contains verse by Welshman
• Shaped like an egg
• Old Roman cardinals recruiting pro like Humpty Dumpty
• Something like an egg gives you 06 for 1000