Try going to Wal-Mart and getting some Goo Gone.
Goo Gone will remove almost any sticky label without hurting the wood.
Wood fill can usually be removed by carefully digging it out or use a nail tap.
I use a product called "Goo-Gone". It's an oily orange substance that smells of petroleum. (I'm in the United States.) I've found that very non-polar solvents like oils (Goo-Gone, gasoline, mineral...
Good ol' yellow wood glue.
Do you mean "stamp"? "mark"? "seal"?