"Are Bliokh and Bloch spellings used to transliterate
the same name, so that these could be the same
person? "

The family name BLOKH, the last letter is "X" in
Russian could be spelled as BLOCH (old translation
rules). BLIOKH is rather unusual spelling.
I think the best is to write to the translator or
project coordinator and to ask for original record, if
possible.

Irene Kudish
Tel-Aviv, Israel