The files of supernova neutrino data kindly made available by Hans-Thomas Janka and colleagues can be downloaded from here.
After the header, the data are in the following format:
The method of using the mean energy and mean squared energy to reconstruct the neutrino energy spectrum is in the appendix of Tamborra et al., Phys. Rev. D90 (2014) 045032.
I will copy over some other progenitor masses later, but this should be more than enough to start with!