  We examine eight known single-eccentric planetary systems in light of
recently released large data archives and new analysis techniques. For four of
these systems (HD 7449, HD 65216, HD 89744, HD 92788) we find evidence for
additional long-period companions. HD 65216c is a Jupiter analog, with a period
of 14.7 yr, $e=0.18$, and m sin $i$ of 2M_Jup, whilst the remaining candidate
companions move on as-yet-incomplete orbits. Our results highlight the
importance of revisiting the analysis of known exoplanetary systems when new
data become available, particularly given the possibility that poorly-sampled
data might previously have led to the detection of a 'false-positive' single
eccentric planet, when the system in question actually contains two (or more)
planets on near-circular orbits.
