Although the experiments and investigations of Pedro Reis and his team at the Massachusetts Institute of Technology are about fluid filled egg-shaped shells did not cover the behaviour of the shell called guitar top, I found the following statement of Pedro Reis quite remarkable, and somewhat related to what we know (or do not know) about guitar top doming:
Initially, the team intended to explore large deformations and breakage, expecting that for small deformations, "everything must be known," Reis says. "Little by little, we realized that was not quite the case."