Not sure if the "F" is obvious enough, but maybe the letters could vary more in style and tightness (the "R" was quite a bit tighter). Again, these are really only color sketches to what could become a larger project. Hope you enjoy!
***Also, a minor correction: My apologies. I mentioned in an earlier post that "B" was Beta, when it's actually "Bravo." Incidentally, that would be MUCH more fun to illustrate.