Mystery Artifact: Rise of the Machines

Greetings!  Please welcome back our Mystery Artifact feature, which we hope will return with weekly posts now that our large exhibits are complete!

Here is today's mystery object:

The object is bucket-like, with a clamp that allows it to be secured to a table- or bench-top.  It includes a lid with instructions (which are a dead giveaway, so I will not post them here!), a handle that fits through the lid, and an interior mechanism as seen below:

Here is an image of the object partially disassembled, but with the interior mechanism still in place:

What do you think this item was used for?  What could it be?  Please post your guesses in the comments section below or on our Facebook page.

If you want a close-up look at the writing stamped on the lid, which gives a big clue to this artifact's use, please visit it at the Museum of the Grand Prairie.  Can't wait to hear your guesses!