  The twistor space of representations on an open variety maps to a weight two
space of local monodromy transformations around a divisor component at infinty.
The space of $\sigma$-invariant sections of this slope-two bundle over the
twistor line is a real 3 dimensional space whose parameters correspond to the
complex residue of the Higgs field, and the real parabolic weight of a harmonic
bundle.
