Hallmarked by this Milan maker, having a variant, and longer rectangular base for pin back.
88th ID – PACCAGNINI Made- 338th Field Artillery Bn DUI. This maker most commonly seen with same oval base that hold pin, but this one is a long rectangular base, and stamped, “C. PACCAGNINI / …LUGANO 15 MILANO.”
Fine- excellent condition with a few stress lines mostly under the enamel surface.