Aero Vintage Books

Yale University just posted a HUGE photo archive; searching "plane" yielded over 900 results (lots of B-24 and B-25 factory shots), and so far there's one B-17E:

Wayne County Airport, a United States Army Air Corps air ferry command base sixteen miles from Detroit, Michigan. Workers inspecting a plane/September 1942

41-2622/FK198; per Baugher:

2622 to RAF as FK198. Struck on ground by another Fortress Apr 9, 1944. SOC.

ETA: Type "Fortress" in the search box and tons of factory shots come up, along with this nice shot of B-17F 42-5460 (nothing in Baugher, AAIR shows it as a trainer at Biggs Field, TX):

Little nuggets out there that you continue to dig out. Good stuff. Amazing how much hidden material remains to be uncovered.

And I'm really glad that you guys keep finding them!