Analysing the appearance of the helmet itself, we can infer a few likely scenarios from the decorations and precious metal sheeting and can build a rough picture of what the helmet bowl may have looked like.
As per all helmets with a sizeable portion of their protective silver/gilt coating remaining, the surface is decorated with some elaborate repousse work. Whilst a common feature of such helmets, we see some variations in quite how elaborate these decorations can be; for example on the Augsburg I and II, as well as the Concesti, the decorations are limited mostly to the outer edges of the plates. On the Deurne and Berkasovo I/Budapest helmets, however, the decorations cover far more of the helmet’s surface area (particularly in the case of the latter two where we see decorative glass gems embedded into sockets).
The latter grouping of these tend to be considered higher status as a result, the prerogative of officers and wealthier soldiers rather than a regular legionary (although this is far from confirmed). We can assume it is unlikely the San Giorgio helmet’s missing bowl had the decorative glass gems of the Berkasovo/Budapest helmets, as they are also seen on the cheek plates in addition to the bowl and the San Giorgio seemingly does not even have an open socket for a glass bead, let alone an intact one remaining (whilst it is perhaps possible as a small section of each cheek-guard is missing, it seems very unlikely).
Without the glass beads, however, this could still remain a high-status helmet; as with the Deurne, elaborate repousse work continuing over the bowl’s surface sheeting, combined with decorative silver rivets, could easily make this helmet stand out a level above the average soldier’s headgear; certainly the headgear of a middle-ranking officer, and maybe a regimental commander. The presence of a piece of horse equipment in the same context could imply a cavalryman but could also be part of an officer’s panoply. The presence of multiple bronze objects also speaks of some form of wealth, however without further information on what those objects are it is difficult to say anything further.
While we may never know for certain how this helmet would have looked when complete, the closest helmet bowls discussed so far that may fit convincingly on top would perhaps be either the Deurne or Berkasovo II; highly decorative helmets with decorative rivets but no glass gems.
The rather mysterious context of the helmet and the missing bowl make this one of the less-discussed ones amongst the community, as it is very difficult to decide who this helmet was used by and belonged to, or even to form a reconstruction of the bowl itself without wholesale speculation.
We can make some estimations based on the context, but mostly we can infer a few details about the owner from the decorative patterns in the helmet’s repousse work.