After more months of guilt tripping over my non-existent schedule, I ended up coming to Germany with a scholarship. While there, I bought most of the missing volumes of Aventurier, namely volumes 3 and 5 of the first manga and volumes 1 to 3 of Kaitou Lupin-den Aventurier, the manga that's been released following the cancellation of the first one. As it stands, all I'm missing is volume 4 of the original release, but that will be coming with my second order from YesAsia. Incidentally, there's been a new 2-volume release called Kaitou Lupin-den Aventurier: Toujouhen, which I've also ordered. It seems it's nothing more than a reissue of the 5 volumes of the first manga, with a few bonuses.
But yeah, now that I actually have the means to fully translate this, I've decided to get back to translating this manga. Here is chapter 4.