I wonder if the person who did the work used the air dry Cerakote, or the bake-on stuff.
I found a Youtube video of someone who did a pistol with the air dry version, the inside of the action as well as the outside was finished. He dissasembled it after using the pistol for a while and showed the wear on the inside of the slide etc. and there wasnt much. He claimed that after trying Duracoat and the air dry Cerakote, he found the CeraKote much more durable.