I had a 6300 - they are old and parts availability vary. Also, these are true mechanical sewing machines - heavy duty to boot. Was the quilt shop a Viking Dealer? If not then the stop was a waste of time - most shops do not service other brands or my guess is that the dealer might not have wanted to deal with it. I too suggest calling Viking Husqvarna directly. They could possibly link you up with someone in your area who could help you out. Or, if there is a Viking dealer in the area - call them.
They are fantastic machines - gave mine to my daughter who uses it all the time. Still running strong. Good luck with it.