Ok, I went down the Joe Baugher serial number route like Bish. No luck ther, but there were B-17's with serial numbers 42-29928 and 42-29930 listed (B-17F-75-BO), so I figured he missed that airframe, because the Army does not randomly skip serial numbers. So I googled "B-17 42 29929" and boom, up came that aircraft here at Avaition Archeology:
http://www.aviationarchaeology.com/src/dbaat.asp?theAT=B-17&offset=750
That B-17F was lost on June 14,1944 due to engine failure while assigned to 222 CCTS (Combat Crew Training Squadron?) out of Ardmore Army Air Field, Ardmore OK, while at Smoky Hil AAF, Salina KS.
So then I googled up 222 combat crew training squadron and came across these photos of B-17s at Ardmore AAF with the same 4 digit nose numbers.
Based on all that, I'm gonna say that photo of your dad with 9929 was taken stateside while that aircraft was a training ship