Reference needed for lower bound on number of guards in three-dimensional art gallery guarding
To my knowledge, Seidel's construction has only been published in O'Rourke's book and nowhere else.

In one of his papers, Seidel even refers to O'Rourke's book for a description of his own construction. He writes on top of page 253 of his joint paper with Jim Ruppert: 
"In his book [9, p. 255] O'Rourke describes n-vertex three-dimensional polyhedra that require $\Omega(n^{3/2})$ guards."


  Jim Ruppert, Raimund Seidel: On the Difficulty of Triangulating Three-Dimensional Nonconvex Polyhedra. Discrete &amp; Computational Geometry 7: 227-253 (1992)