I seriously think you screwed up in several places just from what I can see. Very shoddy work. I am disappointed at your failure to be honest.
In the spirit of the brethren, I have decided that I want you to have the BEST cooker possible, so you should start over and build a new one from scratch.
Meanwhile, to further show there are no hard feelings, I will send you the address at which to deliver this eyesore so you don't have to dwell on it........
Amazing job. Absolutely amazing. I made a sheet metal box without a lid in metal shop about 30 years ago. Think I should try one too?