Not sure in the states but it is easy here.
Phone call,info exchange,tell them what you need.If you buy enough they will even ship it to the tannery for you from the auction house and you will receive the tanned fur if you wish at your home.
I know one trapper that used to buy a couple of lots of fisher coon at FHA every time he could.The auction house shipped them to the tanner-the tanner shipped them to a hat maker-and the hat maker shipped them back to him and he retailed them.
FHA is way way better for people to do this-lots are considerably smaller and the graders are fur guys/trappers.I have found you get a serious mixed bag these days at NAFA-will probably remain this way until NAFA gets their graders properly trained.Lots of the older knowledgeable graders from NAFA are gone.Just my opinion of course.