Surely that should be "moving the rollers from the back to the front", Egyptians were'nt that thick.
On a more practical basis, if was a wooden frame piano in that environment, its dead, a cast iron frame could maybe be retuneable, at some expense, unless it is a Beckstien, why bother to try to save it?, its only an upright, not even a baby grand!.
P.S. I suspect "Fingles cave" or "Orpheus in the underworld" might be contenders.
Always remember, nature is in charge, get it wrong and it is you who suffers!.