Seat bottom unsupported...any way to fix it?

Hey all...I have a 2007 Centurion Typhoon and I'm having an issue where the combing pad on the starboard side gunwale behind the driver is overlapping the fiberglass seat base, creating a situation where the seat is really unstable and slides out when someone steps on it while boarding the boat. First pic is the starboard side in question, second is the port side for comparison.

Is this something that can be corrected with some upholstery work to the combing pad? Only other thing I could think of would be to add some additional rubber/plastic retainers to the bottom, but not sure how well that would work. Would appreciate any thoughts...thanks!