I got curious so I went out with my level and camera. The first pic is of the level setting across the window to show any bowing-in. It looks huge in close-up because of the zoom, but it's less than a half inch. I don't know if it was ever less than that. In the second close-up you can see that all that vibration has worn a couple of shiny spots from the three rubber bushings on the other wall and it looks like there's been some squishing of the longitudinal separator bar, but I don't know that it's more than just something to keep an eye on for now.
It's never too late to have a happy childhood!
Lee, WU0V, and Courtenay, N0ZDT
2011 Rockwood A128
2000 Silverado 1500 pickup
60W solar system
2000W inverter generator