Just of the top of my head and with no particular depth of knowledge to inform my impressions, I would say that
if it is a fake, it is a very good and very old one.
The only things that are slightly
off looking are the hinges for the lid which look a bit too modern and the trim around the bottom and the feet--the wood and finish here with these latter two not quite matching.
The quality of the wood work is very good given the complexity of the form--lots of compound angles to cut and fit. Not school woodworking class joinery.
And there is what we might call (clothing)
sleeve/button wear on the finish in the area defined by the rotation of the crank. If the machine is a fake, it has either been used extensively for a long time or someone has cleverly gone to a lot of trouble to counterfeit the wear.
Cosmetically, if it were on a shelf or fireplace mantel with the lid closed, it would look like a cremation urn/box that might contain some distant ancestor's or favoured hunting dog's ashes.