Hello Theo, I have no idea how much is done your work for the east front. I found today a site on 101 AP, a Li-2 unit flying bombing missions at night. Some detailled losses:
http://101aviapolk.ru/index/na_brats..._rydajut/0-150
including one that could be the "PS-84" claimed by NJG 100 on 21-22 April 1944