I actually burned an eprom and tried it in my real Delta-1, but didn't succeed.
Found out the both CHIP ENABLE's are somewhat different than standard mask-roms. ROM dump was the same as ma_winke_y1d.

And I believe the real Delta-1 does indeed access the table, because it's doing something with these chip enables. So the error should be in the MAME emulation, and I did only correct it for MAME.

When I let Delta-1 (original) start as white, it shows the same moves as Boris rev1, but on the emulation it's plays very differently.