Awesome! I appreciate it.This is more a drum smoker (UDS or WSM) than an offset---you over-fuel it, start just the middle, and let the fire spread out with time. Like the door on a firebox, little vents at the bottom control the rate your fuel is burned and hence your cook temperature. After a fuel cooks, you have the process dialed in. The doors would still allow some moderate interaction if things didn't quite go to plan. (The doors aren't large enough to allow a full size circular grate or fire shield to be added.)
I'm guessing he specialized in ribs (noting the absence of any grills/grates in your pics) hung off that carousel at the top. I suspect he could get 15-18 racks in there. He'd probably re-hang them upside down halfway through the total cook to average out top-to-bottom cooker temp gradients. (The rotational vertical rotisserie ensured any planar gradients averaged out.) You could ask the widow if he left a bunch of hooks behind, although he might have just bent them as needed from a spool of baling wire or old metal coathangers.
These were inside. The circular grate has chains and hooks to hang from. The rectangular ones could have at one point but currently don't. I was contemplating cleaning these up or making/buying/seasoning my own. I'm sure if he didn't have them hanging they were sitting on the bricks.