  A complex ruled surface admits an iterated blow-up encoded by a parabolic
structure with rational weights. Under a condition of parabolic stability, one
can construct a Kaehler metric of constant scalar curvature on the blow-up
according to math.DG/0412405. We present a generalization of this construction
to the case of parabolically polystable ruled surfaces. Thus we can produce
numerous examples of Kaehler surfaces of constant scalar curvature with circle
or toric symmetry.
