At least you have photos - so it can be reconstructed - Fred Wendorf also did a survey I am sure, so at least the positions are recorded for posterity.
I agree, this circle is incredibly important, so it needs to be cleaned up and repaired.
Why not start a conservation charity? Likewise, when I was in Cyprus this January I was sad to see many of the old tombs from the Iron Age C.600 B.C. now under salt water and rapidly deteriorating.