/usr/lib/tcltk/owtcl-1.0/ow.so is in libow-tcl 3.1p1-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/tcltk/owtcl-1.0/ow-1.0.so
/usr/lib/tcltk/owtcl-1.0/ow-1.0.so