I think string "Persiųsti kaip"("Forward as") would be better then current "Persiųsti kitaip"("Forward differently"). I don't saw original translation, but imho it's translated wrong.
Hmz... Only the labels and the tooltip on the button menu are localized in the extension.
I didn't localize the strings for the context menu. Instead I reuse the strings from the main menu Message | Forward As | Inline / Attachment.
Maybe you should report this to the localizers of Lithuanian Thunderbird.
Or maybe I should add these strings to my extension.
Maybe I can make those 5 strings optional too, just like I did for the Danish localization...
P.S. updated Lithuanian translation
Topic should be "Looking for Lithuanian localization of Forward extension"
My bad. Goofy fixed the topic for me...