Sounds like you have some good rework ahead of you. I used the calculator when I designed the 500gal RF that I am just finishing. Found it to be very educational and easy to use for the uneducated.
Since it looks like fire box is to small as I rebuild it I was wondering about making it a fb / grill would use smoker as warmer when grilling dogs / burgers. Take out rack when smoking some type of flat top to do pots of beans on when smoking Remember I am new at this. Thanks for your input
have decided to not proceed with this one. but wanted to get to smoking faster than starting from scratch. feel I need to learn more before i build. bought a used ex competition one off CL. Didn’t think to take photo. Smoked chicken, hamburgers and hotdogs on it for mothers day. Chicken thighs were very good. Chicken breast were a little dry but were skin less. Hamburgers were a little to well done. But all was eatable and had a great flavor. It is a reverse flow. Thanks Frank for your advice and time.