  We revisit models of heavy neutral leptons (neutrissimos) with transition
magnetic moments as explanations of the $4.8\sigma$ excess of electron-like
events at MiniBooNE. We perform a detailed Monte Carlo-based analysis to
re-examine the preferred regions in the model parameter space to explain
MiniBooNE, considering also potential contributions from oscillations due to an
eV-scale sterile neutrino. We then derive robust constraints on the model using
neutrino-electron elastic scattering data from MINERvA. We find that MINERvA
rules out a large region of parameter space, but allowed solutions exist at the
$2\sigma$ confidence level. A dedicated MINERvA analysis would likely be able
to probe the entire region of preference of MiniBooNE in this model.
