I think you want to take a page or several from Gtk2-Perl. Take a look – gtk+ looks very similar to Etk on the C side as far as I can tell, so it should translate well. Certainly your bound interface as it stands is not at all perlish, while Gtk2-Perl turns the procedural struct-based OO interface of C into the typical invocant-based OO with packages and blessed refs of Perl so that it actually feels like you’re writing OO Perl rather than OO-ish C.

Makeshifts last the longest.