Niklas,
Are you referring to the swinging fore end (Lefacheaux) as an underlever ( which is parallel to the trigger bow) that swings down and forward? I'm assuming so, as I've never seen a Husqvarna underlever or even a rotary underlever (screw grip). But if in fact you do have an underlever, I would appreciate a photo or two for my Husky files. As you can see, I openly post any Husqvarna info that I have for the BBS and anyone who asks (occaisonal European requests)