I have both a C version (in the from of a patch to the existing
install-info code),
and perl and python standalone scripts.
I fully agree with Karl that the standalone scripts are preferable.
Unfortunately,
that conflicts with the original motivation, which was to fix Debian
post-install script breakage. I wish they could simply drop the
install-info in this context and started using my Perl or Python
scripts , but I guess compatibility considerations won't allow that.
Note my present address, in the Cc.