Wiley mini-mill manufactured by Arthur Thomas Scientific Co, probably in the early-to-mid 20th century
For preparing finely ground samples of wood, grains, etc for laboratory work
The mill runs smoothly and the speed control rheostat is functional
The output screen is size 40 and appears new.
The only part known to be missing is the end cover, typically glass or plastic, metal could also be used, This piece can easily be made. The end cover retainer bracket is in place and functional.