Re: well i messed up big time
Replacing the head and/or cylinder jug would probably be the easiest, and possibly cheaper than getting a drill press for a hand drill and a bunch of other junk. Sounds what you're looking to replace is the cylinder jug. The head is the part that holds the spark plug that goes on top of the jug. It's not that hard to replace. You just have to use plyers to squeeze the piston rings so that the piston will slide into the new jug. It can be frustrating but its simple.
When it comes to the engine and the muffler, don't waste your time with JB Weld. There's a time and a place for it but it doesn't hold well on parts that get extremely hot and vibrate rapidly.