Can corrosion be repaired?

[AP AVM]

As I begin restoration work on AVM, floor is all frosty white on the top surface, one side lower section of a bulkhead/fuselage former is also corroded. Is there a way to fix this issue. Maybe by changing floor board panels?

Couple guys said, due to this issue, I may start looking for another fuselage. I really don't want to go this route as this is the aircraft for me to restore and fly again.