Outstanding observations everybody, and very informative, as being a complete novice at artillery and firearms dynamics and nomenclature the things noted here really add perspective.
I noted I had been trying to find a long forgotten article on this esoteric topic, and after considerable excavation here in the bookmobile, I found it!
It is titled "Gunners Daggers" Marcello Terenzi, in 'The Arms and Armor Annual' ed. Robt. Held, 1973.
The information in the article pretty much corresponds to all of the observations and notes shared here, but I did find an interesting angle adding to the mystery. Apparantly, just as noted, the stiletto was indeed outlawed as an insidious weapon, and numerous examples of these seem to prevail with numbers seeming nonsensical in comparison to known numerics applying to artillery of the times. These are considered to be stilettos marked in this way to circumvent the law.....but it is noted that the calibers of guns changed over time with use, and the casting of ammunition was anything but standard. While that would seem to explain the variation in scales, but according to the article, measurement was accomplished through a mid point at the barrel, and other 'back to back' means.
What was interesting is that these stilettos were typically noted as Venetian, as they do indeed seem N. Italian weapons of 17th-18th century, but more curious is the 1661 edict that actually granted permission to wear these to 'certain persons'..who were stated 'bonified artillerymen'. This edict was pronounced by the considerably mysterious Council of Ten, while of course a governing body in Venice, believed to have had covert methods of administrating and controlling certain issues.
( the well known schiavona swords of the Dalmatian forces here who served are often marked CX -Council of Ten).....I wonder if any of these 'fusetti' (as termed in the article) might have had that numeric secretly incorporated into the numbers?
Another incredibly bizarre note...to add to the fantasy of early studies of arms, on p.175;
Apparantly there was once an 'absurd notion' that the numbering served to prove to the client of an assassin the depth of penetration into the victims body by telltale blood marks!!! This nonsense must be added to the many myths of weapons lore as surely one of the most ridiculous
I think the information on the more insidious use of these as insidious weapons is completely intriguing, especially with the Council of Ten entry.
It would be interesting to find early methods employed to measure the powder etc on cannon...
did these multipurpose weapons actually serve this purpose with artillery crews, as they are only known from the 17th and 18th centuries, and it is noted that the 1661 edict in Venice, later used again in 1728 in specific granting of permission to someone named Antonio Spadone , and after this these daggers seem to virtually fall out of appearance.
The name sounds suspiciously like 'Andrea Ferara' (spadone=sword).
It is stated than many examples have the numerics almost obliterated (presumably repeated usings and the corrosive powder), but is this sufficient to suggest actual use as stated?
I really appreciate the great input and am always amazed at the knowledge out there! Perhaps we could look further into the mystery of these ?
All the best,
Jim