I call bullsh*&! When it comes to collector quality Lugers, importer marks are definitely a killer. Sure, if you can't find it any other way and want it anyway like Ed stated, or it is a shooter, you may choose one with importer marks. But then that is exactly what you have and nothing will bring that to the value or desirability of an original unmolested collector Luger, period. IMHO if it has an importer mark it IS definitely looked down upon.