This is a Sextant, an instrument that sailors used to calculate their latitude with, by measuring the angle between the Sun (or some other star) and the horizon.
The scale and upper mirror still need a little bit of tweaking so for now you can print one yourself using this guide here: http://www.tecepe.com.br/nav/XTantProject.htm
Use M3 and M2 screws and nuts to hold it all together (using glue is also possible but make sure the parts that need to move can move!)
Oh and you will need two 35 x 15 mm Mirrors, ideally without glass, just polished metal so there is no refraction.
The parts file needs support structures. Otherwise the model is ready to print.