I can only address what I did with my kegger, which is an old Whirlpool. I removed the door liner by cutting it apart with a paramedic's shears and then trimming along the seal to get a clean edge. I cut the plywood to fit under the seal and glued it in place with construction adhesive.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk