Is a miscast 2004 one pence piece of any value it has blobs of unpressed metal on the queens head It's not damaged but definitely miscast?

Answer 1

Coins are struck, not cast.

Any coin with a "genuine" minting flaw may have some value, above the usual, as a collectible coin.

Genuinely flawed coins are not necessarily known about or documented until somebody turns up with one, since they are an "accident" of the minting process, and have escaped detection during quality control at the mint therefore, a valuation cannot be anticipated.

A reputable coin dealer should be able to identify and confirm the coin as genuine and make a valuation.