I too would like to see a hellship movie but I don't think political correctness is the limiting factor. Rather, the whole experience was simply too horrible in every way to make a good movie.
A couple of corrections. About 550 men survived the three ships to Japan and ~400 of 1620 survived the war. (You can find their names at http://people.tamu.edu/~jwerickson/POW/OMrosterguide.html)
Maj. Smothers survived to Japan but died on a ferry while being transferred from Japan to Manchuria in April 1945.
Thanks for the correction. I went back through my files, and Major Smothers did indeed die of pneumonia in April 1945. You might be interested to know that I corresponded with Major Virgil McCollum, the best friend of Major Smothers. He told me that on the leg of the trip from Formosa to Japan water was very scarce. The guards saw this as a profiteering opportunity, and traded water to the prisoners in exchange for valuables. Major Smothers traded his West Point ring to a guard for two cans of water, and he gave one can to Major McCollum.
You're probably right that the story could not be brought to film. We are fortunatel that some of the survivors put their experiences to paper.