Somewhere along the way I purchased a used copy of "Warships of the Imperial Japanese Navy, 1869 - 1945," Naval Institute Press, ISBN 0-87021-893-X, and it has a chapter on "Oilers."
Several classes are shown including Shiretoko, Kazahaya, Hayasui, and Tamano. There's a line diagram for the Tatekawa Maru, and she is listed under "Merchant Ships used as Fleet Tankers," with the annotation 10,009 GRT, built 1935, sunk 24 May 1944."
The box art seems pretty close to the line diagram (including the catwalk set off to portside)and the Tatekawa Maru does indeed resemble a T-type tanker, more so than the other oilers which seem to have taller stacks, more bridge superstructure and less aft superstructure than the T's.
Just about every tanker listed was sunk during the war (mostly by US Subs) - there is one, Kyokuto Maru (10,051 GRT), that was sunk by TF38 aircraft in Sep. '44, then raised and repaired in 1952 and went back to work as the California Maru until scrapped in 1963.
Have fun with the kit!
Mike