Theme author, please read... Rated 4 out of 5 stars
This review is for a previous version of the add-on (0.3.4).
Everything is great about this theme with the exception of the History, Star, New icons, for example.
First, the Star icon is too big--reducing would help. Second, the History icon is too bulky--keep the clock and leave the notepad behind it out. Also, make the New Tab icon bigger--it's too small in size when compared to the New Window button, for example.
In fact, why don't you make all of your icons artistically match your default ones--the Back, Forward, Reload, Stop and Home buttons? The remaining icons look odd and out of place when placed next to your original, dark-gray, aforementioned ones.
Take a look at this other Netscape-looking theme, and notice how all of its icons are the same size and style: https://addons.mozilla.org/en-US/firefox/images/preview/7249/3
Great theme overall.