Hi Alain. This is "Dumbo"'s mission list from Ray, note no 21st. Jan. though he says it's not complete.
"535" is not related to serial, this is her number on the production line at Tulsa,
she was the second in this block (numbers for these B-24H-20-DTs --there were 65-- were 534-598).
Douglas also allocated numbers for their Tulsa-built B-24s, "Dumbo" was no.16058. When transferred to 732BS her name was "The Pistol Packin' Pachyderm" with same artwork.
http://www.usaaf-noseart.co.uk/plane.php?plane=dumbo
Nick