Ok I'm the man - I did it
. I still don't remember where I found the lobber mod but today I've found the last mod to the scatter gun. The chest is on the Brink Island in volcano level. Just before you reach the first platform which breakes and falls after you stand on it - there is a solid platform (after this three "pipes" which you can grab and jump towards the hole). When you are standing on this solid platform turn left - should see this "teleport sculpture" and... that's it
You probably know what to do next.