Intentional Misdirection
Let's think about intentional misdirection. The December painting is one that stands out to me as having a lot of misdirection/red herrings in it.
The flower on the right side of that painting looks like a pretty standard daffodil. The daffodil is the birth flower for March. The clock has a second hand pointing to the 3 and conceals a blue-ish-green-ish gem (is it an aquamarine?). One could -- please don't -- make a reasonable argument that this is the March painting.
Another name for daffodil is narcissus. The narcissus is the birth flower for December. The clock has hour/minute hands pointing to the 12, and that blue-ish-green-ish gem (is it a turquoise?). Just as reasonable to say this is the December painting.
They used the fact that the March and December birth flowers are the same to make it less obvious, to intentionally misdirect our efforts to solve the puzzle. Not to mention the flower on the actual March painting looks absolutely nothing like what you would expect a daffodil to look like.
How do you figure out which is which? You have to bring in the immigration group, i.e. using the Litany of the Jewels. On page 21 we're told that "The Nymphs of Hellas cherish sweet Aquamarine". Aquamarine is the birthstone for March. One of the other paintings is overtly Greek. It becomes a process of elimination.
I've seen hundreds of attempts to prescribe value to that second hand pointing to the 3. Maybe it's just a red herring?
The takeaway here is: what other unidentified misdirection - in this painting, or any of the others - is getting in the way of us solving these puzzles?