the .dat file was the one in the IJN Jyunsen B beta 3.2 18 sen toku I put for download, it is the basic typ 18.dat,
the jyunsen B hull is found as well in my download page along with other stuff, I think the non textured one is there (japsubhull.obj) in a rar file.
I had this trying to re open my new jap tower, with the new 3d object of the Jyunsen B tower so i so that I could id the german tower parts and edit them out, woops !
Jyunsen B thread :
http://www.subsim.com/radioroom/showthread.php?t=134119