Howdy, Folks!
Yup, it's Italeri alright. Last May or so Tamiya released 4 "Italeri Military Models with Tamiya Taste" (I guess that means with the added jerry can sets and figures!).
Besides the Steyr Erock scored, they also reboxed an Sd.Kfz. 234/2 Puma, a Mercedes Benz L3000 truck, and a Kfz. 15 Horsch (sp?).
That looks like the same packaging as I've seen here. There's still plenty of Japanese on it, from what I can see!
Does it say "Made In Italy" in the lower righthand corner?