Hi Orion. Well, I've checked all my sources, and can only come up with the following.
There was a William B. Wentz, pilot of B17G 43-39126, of the 838th Sqn. No other info is listed for this aircraft, and no mention of any name or nose art. This info is from the 487th Association, the following is from my own references.
The 338th's code letters were 2C, in black letters on the rear fuselage, and the group carried the 'P in a square' ID letter on the fins of the B17's, a white 'P' in a black square.
There is a colour profile of a B17 from the 836th sqn., coded 2G, in Roger Freeman's 'The Mighty Eighth', and a similar profile on the 487th Association web-site, which give a general idea of the overall colour scheme for the period, when all of the Group's B17's were in 'natural metal' finish, with yellow fins/rudder and fin spine. The Group's aircraft also wore a yellow and red diagonal stripe (in an inverted 'V' shape) on the outer starboard wing, the yellow stripe inboard, and had the outer wing tips in yellow. I believe the tailplanes were also yellow, and some aircraft also had red forward engine cowlings.
I haven't been able to find any pictures of this particular aircraft, but if I do, I'll let you know.
Sorry the info is a bit 'thin', but I hope it helps a little.
Cheers,
Terry.