  Understanding the evolution of massive binary stars requires accurate
estimates of their masses. This understanding is critically important because
massive star evolution can potentially lead to gravitational wave sources such
as binary black holes or neutron stars. For Wolf-Rayet stars with optically
thick stellar winds, their masses can only be determined with accurate
inclination angle estimates from binary systems which have spectroscopic $M
\sin i$ measurements. Orbitally-phased polarization signals can encode the
inclination angle of binary systems, where the Wolf-Rayet winds act as
scattering regions.
  We investigated four Wolf-Rayet + O star binary systems, WR 42, WR 79, WR
127, and WR 153, with publicly available phased polarization data to estimate
their masses. To avoid the biases present in analytic models of polarization
while retaining computational expediency, we used a Monte Carlo radiative
transfer model accurately emulated by a neural network. We used the emulated
model to investigate the posterior distribution of parameters of our four
systems. Our mass estimates calculated from the estimated inclination angles
put strong constraints on existing mass estimates for three of the systems, and
disagrees with the existing mass estimates for WR 153. We recommend a concerted
effort to obtain polarization observations that can be used to estimate the
masses of Wolf-Rayet binary systems and increase our understanding of their
evolutionary paths.
