I haven't look for this extension, but if it's like I think, you will have a hard job to make it work.
I have tried with some xul help system from Nvu/Kompozer, Seamonkey, xpcomviewer and I never can make it work. I think that some services are missing. Our cleaning in mozilla is good to make K-Meleon thinner, but it don't allows some features. With a version, I made it work partially, but not as it ought to do.
So I haven't continue it.
Good luck ...
A+
Mozilla/5.0 (x11; U; Linux x86_64; en-US; rv:1.9.1.17pre) Gecko/20101211 Ubuntu/12.04 (precise) K-Meleon/1.6.0
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:1.9.2.14pre) Gecko/20101219 Ubuntu/12.04 (precise) K-Meleon/1.7.0
Web:
K-Meleon Extension Setup (French) and
(English)
Web:
http://jujuland.pagesperso-orange.fr/
Mail : alain [dot] aupeix [at] wanadoo [dot] fr