Five scraper arms were missing. The used parts place didn't carry them and the local Case dealer wanted to charge me $112 (!) each.
(Click on any picture to make it bigger.)
The scraper arm is the red piece on the welding table. It's stamped from 1/4" plate and has a few angles and holes in it. My replacement parts are made from 1/4" steel strap and plate pieces that are welded together.
The discs cut through old plants and bury them in the dirt. While doing this dirt is often stuck to the concave side of the disc itself, and if there isn't a scraper, causing it to plug.
As well as the scrapers there are a couple of new hydraulic hoses, four new tires, and assorted other things to fix on the disc.