I have the Ace 4-60 plans - the sideview of the fuselage does show the CG at the main spar.
I took mine off with my close-up glasses on once, and of course couldn't see it past the end fo the runway. The last time others saw it, it was coming down nose first in a slow roll. Landed on an unpaved street away from the field, tore off the gear and broke the prop. That's all - sometime the R/C Gods smile upon us. Enjoy yours, Eloy