Yes, I was wrong. I found this in a book about silver and goldsmiths
Originally Posted by RC Christian
"While in Christian art the carpenter's rule is a standard attribute of the apostle Thomas, English goldsmiths invariably endowed him with the spear with which he was martyred. It is St. Matthew who, generally before 1560 and sometimes even after, is represented on apostle spoons carrying the carpenter's square to symbolize the church he is said to have built for the King of Ethiopia."
Matthew is depicted twice, both as evangelist (sitting to the left) and as apostle (standing in the middle with the carpenter's square) on the top of the KJV title page.