Anything can be restored, it just depends on how much time and money you want to invest in the project. There's a point at which it's not worth fixing, versus getting another one that's in much better condition, and can be enjoyed right away. Then there's the folks that just love a challenge, and don't care how long it takes. You didn't say what year, or model pop up you have.
2012 Jay Flight 19RD
2016 Ford F150 XLT 2X4 SC 3.5L Eco Max Tow
2010 Tundra TRD DBL Cab (Traded)
1 Spoiled Dog