I think these folks are still in business. I posted this a couple of years ago. Haven't needed parts since.
I have a Vicon disc mower. It's an older model (CM-240), I bought used. It needed some repairs. I got all the information on the cause of failure from Mike at Vicon warehouse in St. Charles, Mo. (800-237-0562).
I tried to get parts from Heritage Tractor who is the local JD dealer and Vicon Dealer. They had no parts at any of their stores and had to order them in, and I would have to pay freight. Mike told of their busiest dealer who is/was Mordt Tractor (636-263-8575) and Darrell Strielsler is parts mgr. All very good to deal with.
The problem with the mower was the owner had removed the flow restrictor fitting and the bar came down too fast. After hitting the ground too many time the metal failed. I ended up having a welding shop rebuild the broken metal and beef it up and then made my own restrictor at a $5 cost instead of $70!