It helps to keep in mind that Southern Italy was controlled by Spain during the period. So many of the miquelet style locks from the South resembled the Spanish locks.
The so-called Roman lock is thought to have been developed in Central Italy, with it's wide spread use in the Central and Northern areas.
Unlike the Spanish style locks, the Roman lock mainspring operated on the TOE of the **** versus the heel. Also, the Roman style locks often have what you might call a dual sear arrangement. A separate sear for each **** position.
Of course, the snaphaunce lock, when first introduced was very popular throughout much of Europe and beyond. But for some reason the snaphaunce had a renaissance in Italy sometime during the late 18th and early 19th Centuries. Primarily with the aristocratic classes for their personal pistols. So some will mistakenly think a certain Italian snaphaunce pistol is older than it actually is.
I'll post some pics of a Roman style lock next.
Rick