“What did they do back then if they made a typo ? Did they execute the chiseler ? Is that where the term chiseler came from ?”
Typically, they would write out the message with chalk or some such; it would be proofed, and then carved. So mistakes were rare. Yes, they would lightly carve out mistakes, then write over the marked out area. It was subtle. Frequently in Egypt one pharaoh would carve over the name of some other ruler who was disfavored and put his name in place. They can now figure out the original name by impressions in the rock; I think using x-rays.
Without looking it up “chiseler” comes from the practice of shaving a bit from the outside diameter of coins back when they were made of silver or gold. This is why USA coins historically made of precious meal (quarters, dimes, etc) have the serrated edge — so you could see if they have been shaved.
Thanks MWT!