I was issued those in Italian army.
The early vest was the C3, issued circa 1995. In hindsight it was quite advanced for the time, It had front back and side plates and It was a front and back panel, not front closure which Is quite a weak point that US carried over to the interceptor. Kevlar panels. Stable, but It was cut too long and neck kevlar was quite high. I think they had early deployments in balkans.
Then in 1998 came the widespread issued Ap98 "the turtle". In was superseded in 2009 (even if fielded until much later) by a iotv Copy with ceramic plates and balcs shape soft armor, the NC4/09.
I think the plates you have come from this Ap98 model.
That too It was quite bulky, It had extra groin and theoat/cervical spine hard plates. I think the weak point was the shape of soft armor as It was a single piece jointed on One shoulder, not two separate panels, so shoulders were bulky, not that you really shouldered the rifle in your shoulder pocket.
Many colleagues in Afghanistan had Little Faith in those plastic plates and stuck private purchase ceramic sapi style ones.
I am honestly thankful and grateful to you showing me that the issue ones i wore would have worked.
Ap98 vest Is in background, but It Is the same sold by the sportsman guide
In Afghanistan local tailors would make green molle vest covers that would take the Ap98 inserts and plates, while an Italian brand would make One too that had a Quick ditch cable. I have both still in a box somewhere.
I have worn the plates alone in a carrier, without backers (May have been wrong, remember Many US soldiers would do the same with Sapis that are not standalone as well), for more of a low vis High Speed work.....well they aren't definitely multi curve plates, more like taping a brunch of hardcover books to your chest
Edit: if It May be of interest to someone the soft armor behind this plates was NIJ 2 rated, not 3A. Layered Kevlar and uhwpe polyethylene pliable sheets backed with polyurethane foam to cushion the impact shock. Definitely thicker than a standard police nij2 vest which Is definitely concealable.