Has anyone seen pictures of a Soviet B-17?

Quite a few, yes. Carl Geust has published a small number in RS4, mentioned above. It should be borne in mind that these aircraft were not operated in any kind of ‘combat’ capacity, rather in a training and familiarisation role. Also quite often in an executive transport capacity, as well.

The vast majority (if not all, eventually) were de-militarised (guns and such removed), appear to have been only minimally re-painted (with Soviet markings, for example), and a fair few received civil registrations. A number were in service as early as 1944, and the Yanks appear to have had no disagreement with this kind of utilisation, even supplying spare parts and assistance on more than one occasion.

p.s. Ken, well done for ‘flying the flag’ on these posts, mate!