  TeV-scale seesaw mechanisms are interesting due to their potential
testability at existing collider experiments. Herein we propose an
E$_6$-inspired model allowing a TeV-scale pseudo-Dirac singlet neutrino seesaw
mechanism with naturally sizeable Yukawa couplings of $\mathcal{O}(10^{-2})$.
The model also contains new U(1) gauge interactions (and associated $Z^\prime$
bosons with which the singlet neutrinos can be produced at colliders),
typically long-lived colour triplet fermions, SU(2) doublet fermions, and a
complex scalar - potentially all at the TeV-scale. Additionally we identify
three possible explanations for the 750 GeV di-photon excess.
