The battery tray had a rust hole in roughly the shape of the bottom of a battery. Years of battery leaks caused this area to rust at a faster rate than the rest of the bus. The repair is mostly complete, all that remains is to finish grinding and shape the repair to more closely match the crease lines of the surrounding metal. The repair required working in an extremely confined location hence this is probably one of the ugliest repairs I’ve done lately; it won’t be noticeable after the body work is completed.