Fermont built the 803. As Guyfang and others have said, cheaper to throw away, and get a newer one that works. The schematic in another post looks similar to the tech drawing I have on file. OEM VRs were riveted. No repair authorized for field maintenance. Many have tried, and some have succeeded, some failed. Then they called Dave so the old guy could say request a new regulator. You should see the birds nest in the main gen created after some tried to be creative. $$$$ main gen time. We pushed a new regulator with a main gen all the time. Glad someone reversed engineered this one. OEM was expensive to change just before AMMPS Gens came in at over $450 AMDF price. 100% increase in price since 2000.