The Lungbursta is an Ork Assault Tank coming from the good old days of Epic, the days of oddly phallic vehicles and demonically possessed toy trucks. The Lungbursta was just one out of many Ork vehicles that just did not make the cut from Epic into modern 40k tabletop gaming, but unlike the others where the designs were so god awful and names so cringeworthy, the Lungbursta seems to be the exception....well, except from its odd name but whatever.
As an assault tank, the Lungbursta is dedicated to going headlong into the front lines with the infantry. Yeah, it's pretty weird how back in Epic and early 40k, the Orks actually had a lot of tanks, from the traditional main battle tanks like the Gutrippa and Gobsmasha, to the heavy tanks like the Bonecruncha and the Bonebreaka and than to the tank destroyers like the Spleenrippa and Braincrusha, the Orks had a lot of armored diversity to pick from. Contrast this to modern 40k where the Orks have so little armor that they might as well be Tyranids that talk in a cockney accent, seriously the closest thing they have to a traditional armored division are Looted Tanks, Kill Tanks and Battlefortresses.
Still, despite being classified as an assault tank, the truth is that it is more like a tank destroyer in design than anything else. Although it may look like it has a turret, it is actually just a weirdly enlarged view port. The gun itself is fixed forward between the front hull and the view port. If it was an assault tank, it would have been a poor one at that as the Lungbursta must move itself to even aim at a target. Therefore, it should be far more accurate to put it in anti-tank divisions. This classification just might be the result of GW basing it on World War 2 German vehicles (in this case it bears resemblance to the Sturmtiger and Jagdpanther) and many German tank destroyers of the era, most notably the StuG 3 werw envisioned and thus named as assault guns.
Furthermore we have its...odd name. We aren't sure how this vehicle can burst a lung. A strange set of words. The most likely way would be if the pressure waves from the gun firing would 'burst' the lung of anybody near by, but surely bursting the lungs of any nearby exposed infantry would hardly be most dramatic thing to happen when you pulled the trigger on this thing.
Other than that, the Lungbursta remains one of the few good looking models from the age of yore. As of 8th Edition, the Kill Tanks from Forge World are probably the Lungbursta's closest living descendants, Specificaly the Kill-Bursta which shares a similar name & role as a Super-Heavy SPG, it may well be the Forge World modernisation of the old model.