Antique knife

[ALEX]

Originally Posted by Jim McDougall

... It would be equally possible for this knife to have come from Styria...

I also agree. These marks are common on blades of vast Celtic origin, which Styria was part of. One theory is that they indicated quality of the blade, with one being low and three being top. Here's from "Celtic Long Swords with Punchmarks" by Duleba Przemyslaw, Institute of Archaeology, University of Warsaw: "The blades of certain Celtic swords were marked with punchmarks made with specially prepared stamp. The marks were punched in the top parts of the blades of two-edged swords (both in long swords as well as short ones with anthropomorphic hilts), usually a few centimeters below the hilt. Single punchmarks are most common, however marks in groups of two and even three have been found. Some marks were inlaid with gold, silver or brass. There have been various interpretations of the function of these punchmark. Attempts have been made to prove that these marks are the signs or “brands” of specific blacksmiths, and also signs of property, custom made for selected warriors,however, the most probable answer is that these are magical-religious symbols...". This refers to earlier Styrian swords of course, but could spill into adjacent/later periods.
For the reference, you may see the complete publication HERE