Bob Schefter in Fergus Falls, just 50 mi east of Fargo specializes in rebuilding Super Cubs and is an A&P. He covered and painted our Super Cub, N18SY, and I found him to be a no nonsense straight shooter -- a guy you can trust.
His phone numbers are:
Home/shop: 218-739-0818
Cell: 218-205-0463
Larry Linderman, Valley City ND. Spent a lifetime on tube and rag, plus maintains some sprayers. Dont know if he has retired yet or not. His business was General Air Services.
You might try Keith Schonert at D54 (West Fargo). A good guy and Super Cub Knowledgeable. It's been a few years since I've been up that way, but these are the numbers I had for him :701-282-3786, 701-277-5035.