There are people out there who suggest that the enamel can be repaired with a food safe epoxy, but most experts and manufacturers will not recommend using it for cooking after the repair.
Personally, I would not cook with vintage enamelware. Toxic metals have been used in the past to coat iron. These include lead and cadmium. Please do not use damaged enamelware. Chipped or worn edges can break off and wind up in your food.
If I were you, I'd use the pot as a display piece. Use it to store small items, as a container for a flower arrangement, to store recipes, or anything your imagination can come up with.