A few links you might find interesting (you may have already found these):
(A Link was from removed here, see alternate links in post 4 below).
Regarding Soviet Aviation Gas, supposedly they received a lot of their fuel via lend-lease.
http://www.oilru.com/or/47/1006/
I have seen a source say that 59% of their aviation gas was via lend-lease.
There may be another factor at play here, as discussed in a few other threads:
http://www.broquet.co.uk/history.htm
http://www.carburetters.co.uk/Fuelcat.php
http://forum.il2sturmovik.com/topic/...oviet-service/