Started out as this after my son dropped it.
Ground the ends of a rubber mallet for a smaller end.
Started banging in the dish.
Stripped the paint and then this.
Masked off the dish since I will accelerate the rust in this area and painted the tank.
Once it dries good, I'll sand the transition from the paint to the raw metal to reveal the primer around the edge, do the rust treatment and coat with a satin clear.