Welcome to the forum.
Yes, SOME sellers on KSL are a bit nervous as to whom they sell their weapons to: but, IMO, it is out of responsibility to the general public that they are hesitant. Do you best to ease their minds. Maybe go get yourself a background check done and carry it with you to put their minds at ease.
Of course i understand the law, however, you must understand that these people are selling (potential) "Death Devices" and are concerned as to where they go.
Good Luck, post often!