a win32s version "should" be possible. it's been a while (~4years)
since i've spent anytime in details of win32s, so i'm probably
forgetting something. a 16bit version is not possible.
you might try grabbing the 32bit binary and just see if it will
run on 3.1x (assuming you already have another win32s application
installed). or better yet, grab the source and see what it takes
to build it for win32s.... let me know what happens and we can
update the website and/or source to include support for that
platform.
jeff