By miss-assembled he might mean that a 357 cylinder and barrel were installed on frame already stamped model 10 making it into what is actually a model 13

I had a gun come to me completely screwed up. It was marked 629-1 and had a 44 mag cylinder an 8 3/8 barrel. I had to replace the barrel with a full underlug 5" 45 barrel and ream the cylinder to 45 colt to make it just right.