My 503cx has the same problem but not to the extent yours has. I suspect the heat and humidity are not helping your situation.
I recently had my camera body repaired by David Odess, a factory-trained Hasselblad repairman. I asked him about replacing the material (called "palpas," don't ask me why.) He said it requires a complete strip-down of the camera body and would cost more than the camera is worth.
Hasselblad goofed on their materials testing on this one.