Abstract: In a previous paper \cite{AGM} we computed cohomology groups $H^{5} (\Gamma_{0} (N), \C)$, where $\Gamma_{0} (N)$ is a certain congruence subgroup of $SL (4, \Z)$, for a range of levels $N$. In this note we update this earlier work by extending the range of levels and describe cuspidal cohomology classes and additional boundary phenomena found since the publication of \cite{AGM}. The cuspidal cohomology classes in this paper are the first cuspforms for $GL(4)$ concretely constructed in terms of Betti cohomology.