Lewill, that may be the right call. There were several canals in upstate New York.
Branson, I think the opium boom in New York was over by the time this chest was built in the 19th century.
Opium boom all over all ready?! Oh drat. Did they have grapes yet?
The thing is, I've never seen a caulk removing tool that looked anything like this. The shape of the blade, though, is a very common horticultural pattern, especially for harvesting grapes and herbs, has been over many years time.
An argument against it being a caulk removing tool is that none of the other tools are shipwright's tools, and no caulking mallet, no caulking irons. There are no chisels for the heavy work required -- all the chisels are tanged chisels and not one socket firmer, mortiser or framer.
I think you are right on the money about "The Human Figure." These are about the proportions needed by a sculptor.
Craftsmen relentlessly steal the tools of other trades that serve some need. Maybe the guy found some special use for the little sickle. Maybe he harvested rose hips on the side... But as a caulk remover, that blade would die in a day's work, seems to me.