When this happens, it almost always means the hinge is out of adjustment or set too low at the back of the kiln.
With air moving through the garage, you will minimize the corrosive effects of clay/ glaze fumes on exposed metal in the garage and on the outside of the kiln.
Corrosion on a kiln is perfectly normal... mostly because it is a kiln! Hot-to-cold-to-hot environments, plus all the water vapor, not to mention sulfur, fluorine, carbon etc.
The motor extends 7" off the wall. Motor dimensions are 8" x 7". Wall plate dimensions are 10" x 8", and the tube through the wall is 4" Diameter x 12" long.
All the elements will need to be replaced. For example, the ohms on the J230 208 volt element circuits should be around 14.2.
On most L&L Kilns this is very easy to do. It is a matter of re-distributing the wires between the kiln fuses or relays and the main powerblock inside the control box.
It is possible to convert a J230 manual kiln into a JD230 automatic kiln.