besta.cpp is now bus/vme/vme_cp31.cpp. It was probably a customized version of Force CPU30 series board. There are some technical manuals in Russian, but no schematics.
HCPU30 board is more interesting, as it has onboard SCSI and Ethernet supported by MAME, a Linux 2.0 port with source, and schematics (but no PAL dumps). It needs significant updates to DUSCC emulation, some changes to DP8473, to NSCSI HD device (1024-byte sector buffer instead of 512) and probably more, as Unix and Linux weren't stable when I managed to boot them. I am trying to untangle my wip DUSCC code now