Package format is only minor problem, because it's realively easy to repackage .deb files to .rpm(and vice versa) using 'alien' tool (and fixing differently named deps in some cases')

But as other stated the problem relies indifferent software stacks, SailfishOS is much more newer than Meego/Harmattan, and both got some propprietiary libs, provided only as binary blobs.

But it's worth trying recompiling it. It's not hard to try (there are live distros provided with Harmattan SDK included), but fixing incompatibilities may require some basic programming tooling knowledge.
The most challenging differences can be C++ differencies and Qt4->Qt5 conversion (there are some Qt5 builds available on OpenRepos I believe anyway)