Hoover (along with Orion, London, and Gefion) was one of the sub-brands of the Danish Miller Pen Co., started by Johannes Iversen in 1908 – although the Hoover name didn’t appear until the 1930’s.
This 883 is very similar in design to the Miller 898 (link) – with a couple of notable differences. The Hoover is a button filler instead of using the “stretch-vacumatic” filling system of the Miller. Possibly as a result, the Hoover does not have the transparent portion on the barrel as is found on the Miller. In addition, the design of the cap bands of the two pens are somewhat different.
The pressure bar of the Hoover is an interesting design in that it is attached to the inside of the barrel instead of pushing against the pen’s section (which is smart, since it’s a friction-fit section), or hanging from the top of the barrel.