Btw, my first shot, after setting the base, was to set a R/R spike, with x in top, nearby, for a "more preserved" base point. That silo may not last.... But makes a great base for the life of this job.
Nate
I'd worry about movement in wind, and perhaps staying in a different position after a high wind. Also possible movement as the sun heats up one side more than the other while you work.
Nate,
The bottom corners of that T-2 look an awful lot like those of my T-2. 7 Years old.
JA, PLS, SoCal