Most 18th century moulds I've seen, civilian or military, did not have sprue cutters. Especially the moulds made by gunsmiths - the "rifleman's mould" or "bag mould" - would not have had a sprue cutter typically.
Filing a cherry and forging a ball mould to fit the bore used to be part of a gunsmith's skill set. Hand forged rifle barrels from the American frontier were not uniform in size - they went with a rough "balls to the pound" measure. Caliber as we know it wasn't used in descriptions of rifles, or when they were ordered. A new rifle would have had a mould made to go with it.
Also, wrought iron barrels that saw heavy use got freshened out with some frequency, and re-cutting grooves and sharpening lands (in addition to re-crowning) was also part of the gunsmith's daily work. After a few freshenings, a new ball mould would be needed.
I am sure there were factories in England and elsewhere that produced moulds of any description, but as to markings I don't know. And of course for military use, since those arms were built to a standard bore size, they had uniform sized moulds issued to the troops.
There' a company called Rapine Moulds that still makes a high quality "bag mould" as you picture there, and Track of the Wolf also makes a good similar model.
