Thanks, Glen and Erik
Just to add to Erik's information, the ordinary paper that I use for the wheels (80g/m2) comes out at 0,112mm, or so. I made a roll from a veeeery long paper strip and measured the diameter to get two solid digits a a probable third...
The fuel tank is typical on Halinski kits of German planes. Inner and outer parts are drawn with unaligned joints, so that there is no need for tabs.