This lovely blue pen is an Eagle.
Which sounds very American, but in fact the Eagle Pencil Company was founded as Vera-Bleistift-Fabrik in Fürth, Bavaria in 1856. A few years later they established a branch in New York City and made quite a few pens in the US.
The Eagle line was decently high quality; they also had cheaper pens labeled EPENCO.
The nib on this one is medium with a touch of flex, and gets impressive shading from Sheaffer Skrip Blue. This particular blue-and-silver celluloid pattern can also be found in green or red, also from Eagle. It's quite pretty and has nice chatoyancy.
One of Eagle's claims to fame is that they experimented with glass ink cartridges, decades before Waterman debuted the C/F. I have one of their cartridge pens, which is brass and hexagonal. The feed is missing, and finding whole cartridges is nearly impossible, but it's still a cool bit of pen history.
