I think you can safely assume they were replaced. If this is the coach I think it is, it was used fairly hard for the first couple years (cross country trips) and then parked in California and snowbirded in all winter. It probably has seen a ton of use.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9473.8 (as of 6/18/21)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR