Yes, Daokou roast chicken is very famous now, but Daokou iron pot was very famous before Daokou roast chicken. Now the skill of crossing the tin pot has been lost. Therefore, your crossing tin pot has great collection value and appreciation potential. As for "point copper", it is a sign that all tin pots at the crossing must be marked, indicating that tin contains a small amount of copper. Without copper, the strength of tin is not enough, just like if other metals are added now, tin becomes tin alloy.