"When we arrive at the epoch of the Amatis-i.e. during the seventeenth century-it had ceased, we may say amost enirely, although it survived in the ornamentation of the fittings, such as the finger-boards, tail-pieces, pegs, and bridges. We have seen two violins, the work of Nicolo Amati, which were gracefully embellished with inlaid ornament: in one of them the ornamentation consisted of double purfling, and a fleur-de-lys inlaid in black at the corners of the back and belly, interspersed with small precious stones, while a design of similar character was let into the sides at the blocks."
later in a footnote
The time frame of Stradivari's life makes him contemporary with Louis XIV and Louis was responsible for initiating several academies perhaps his music academy each bore an image of the city it represented and the founder of the academy (another avenue to look into). I have not done much in the way of researching this week because I have tried to fine tune (no pun intended) my proposal, so that I can be ready to approach possible advisors.
"The gigliato was so named because it bore the device of the Florentine giglio, or iris (fleur-de-lys), the emblem of the Republic, as it is to-day of the Commune of Florence."