Sending Unit Float Question

Hello,

I have a '68 Dart 270. For quite a while now the fuel gauge has always read about E, even with over half a tank of gas. Now, I've taken the sending unit out to see what the problem is. I immediately noticed some fluid inside the plastic float, I assume it's gasoline. Is that normal? I don't understand how fluid could be in there to begin with, I didn't see or feel any leaks. The unit works correctly when moving the rod up and down (i.e. the gas gauge goes to Full). So, before I proceed any further, I would like to know if fluid inside the float is normal or not. Thanks