Maximize Thunderbird composing area

Well, I finally got feed up with AspireMail (Could not set encoding to Japanese, among other issues) so I installed Thunderbird via App Installer so version 2.0.16 I believe, but version should not matter for my problem.
I did my best to search online with google and also here in the forums but no luck, also no extensions that handle this issue.
As you may know real estate is valuable on the One, therefore how the hell do I get rid of all those "To: Fields" on the composition window? Why do I need four freaking To:Fields? Maybe I just do not know the right terminology to find what I am looking for but I stumbled around the advance config hoping to find a setting, but I can't seem to find any setting that I can reduce the number of visible To:Fields.

Thank you in advance if you have an answer.
tokyoturnip

 

Code:

cd /usr/lib/thunderbird-2.0.0.16/chrome
unzip messenger.jar
sed -i 's: rows="4": rows="2":g' content/messenger/messengercompose/messengercompose.xul
mv messenger.jar messenger.jar.bak
zip -r messenger.jar content

 

Nice..
Thank you very much, I will give it a try when I get home.
Based on what i see, it looks like that secret setting I was looking for.
Too bad it can't be set in advanced config. Maybe it can be if a key is created.
Anyhow, thank you very much.