AN ILLUSTRATION OF STONEHENGE AND ABURY IN THE COUNTY OF WILTS POINTING OUT THEIR ORIGIN AND CHARACTER THROUGH CONSIDERATIONS HITHERTO UNNOTICED
BY H, BROWNE
Click to embiggen - quality not good.
Note how Stone 14 is propped up and that there seems to be a visible stone under the north east corner of Stone 55a (the fallen stone of the Great Trilithon's bottom part). It might be a packing sarsen that has been uncovered, but I'm not sure.
Stukeley also pictured 14 propped up, and 59 slightly raised;