For those who don't want to read through the whole report, I'd summarize it this way:
"Peacemaker" was a wrought-iron gun, meaning it was made up of many smaller pieces of iron that should have been solidly welded together by heat and the impact of a 15,000 lb. forging hammer. The pieces the maker began with were typically 4 x 4-inch cross-section, eight feet long.
Franklin Institute concluded that basically the "Peacemaker" was made with iron of less-than-typical quality, and that many of the welds they examined were either very imperfect or nonexistant. They were able to pour oil through one area which was supposed to have been welded, and insert a wire through another. They also observed many instances where sizeable areas of either oxide or slag were present, preventing the separate pieces of iron from being joined as they should have been.
For those who read it, what other important conclusions should be mentioned?