I send all my mags to Arn-Air for overhaul, Airboat and Aircraft. He is in Bayard, Iowa. Phone 712 651-2255. The shop is an FAA Certified Repair Station. He can fix anything and the prices are very reasonable. I'm sure he would have the parts you need. I don't think you want unairworthy parts in you magneto.
You could try Gary Barber at Outlaw Aircraft Engines in Plant City, Florida. His was the only engine I ever got from Florida that did not have defective mags.