The locking wedge version is definitely a factory item, because if a conical version was modified, a slot would still be present on the backside of the angle cut, and the machined tapered/conical recess would still be there internally. As the stems penetrate the steerer at equal lengths, the wedge block is most definitely factory.

I traded a Record Offroad crankset for a bunch of parts from a collector in town, and these were in the deal.

If anything, the locking wedge version is probably a later rendition, as this design is easier to manufacture, and the Cinelli logo insert is not as quality (shiny and crisp) as the conical version's.