Excellent stuff.
Here's a link to some research a fellow has done on the crew of Mom's cousin, Lt. William Pflug.
http://members.tripod.com/richardwhite1/id66.htm
The site is mostly about Jim Eppenberger, the navigator, who was relative Billy Pflug's best buddy on the crew (Billy is front row, second from left in the photo). Their regular ride was "Johnny Walker," but were in a different aircraft when they went down on 4/24/44. A flak hit over Friedrichshafen took off much of the left wing, the plane rolled inverted and blew up--about 7 or 8 seconds of he** and then eternal rest.
If your grandfather was there as late as March or April of '44, they might have passed each other in the chow line.