The part about mutilation is included in the Baltimore Catechism in the comments after the teaching about the 5th Commandment. I can’t remember whether or not they included that in the current catechism.
I only know what I was taught, and perhaps there are some other people on this forum who were around in the 1950’s, who remember the same thing.
Some people think that the Church never changes anything. I beg to differ. In the 1950’s, it was a mortal sin to cremate someone who had died or to request cremation for yourself. People who committed suicide were denied a Catholic burial. There were very few divorces among the people at church and even fewer annulments. A divorced woman at church was considered to be some sort of a “loose woman,” and it was questionable whether you would want to be her friend. It was considered much more shocking if someone got married “outside the Church.” If you found yourself pregnant out of wedlock, it was too shocking to even mention. You would have to move to another state to help an aunt who needed live-in help, and then you would come back with no evidence of a baby. Capital punishment was considered just fine.
Sometimes I wonder why some of these “traditional” Catholics want to go back to all of that! I personally much prefer the more modern version of the Church!