cunho
substantivo masculino
1. stamp;
2. seal;
3. coiner's die, matrix;
4. hallmark;
5. coin;
6. type;
7. NÁUTICA belaying pin;
8. cleat;
cunho de cabrestante whelp of capstan;
cunho grande kevel;
o cunho da verdade the stamp of truth;
ter o cunho de to bear the stamp of;

Then use "signatures" or "rubber signatures" for "chancelas"


chancela
substantivo feminino
1. seal;
2. the great seal;
3. signet;
4. stamp;
5. signature;
assinar de chancela to sign with a rubber-stamp;


Mike :)

hope this helps

A "cunho" is tha metallic piece used to strike the side of a coin, ussually known as a die. Dies aren't only for coins, they can be made to strike paper or other materials.