Too bad they don't show the serial. Taking a fairly educated (by the Baugher listings) - guess: B-29-BW MSNs began with 3325 and seem to be consecutive. Including ten B-29s built by Bell-Atlanta and Martin-Omaha which were in the same count, the 1,000th Wichita Superfortress would be MSN #4335, 42-24674:
Joe Baugher wrote:
24674 (499th BG, 878th BS) shot down by Ki-46 over Chiba, Japan Apr 7, 1945 while on mission to Nakajima aircraft factory at Tokyo, Japan. MACR 13625. 7 crew KIA, 4 bailed out and became POW.
Can anyone verify whether '674 was indeed counted as the 1,000th Wichita B-29?
(Edit: it wasn't - see below)
_________________

All right, Mister Dorfmann, start pullin'!
Pilot: "Flap switch works hard in down position."
Mechanic: "Flap switch checked OK. Pilot needs more P.T." - Flight report, TB-17G 42-102875 (Hobbs AAF)