While in the CBM IEEE mood I took out a status-unknown CBM 2022 tractor feed printer I had tucked away in the corner. My son was messing around with the form feed button while I was setting it up. Long story short, we discovered that if you hold down the form feed button and power the printer on at the same time, the printer will print diagnostic test characters (continuously). By analyzing the printout, I learned that the 2022 is at least mechanically OK in that the paper feeds and the printer prints characters correctly. There was even a little bit of ink left in the ribbon. This is a nice feature because it saves a person the trouble of having to plug the printer into a system. I bet this works for other older IEEE printers esp. the 2023 and the Europen 3022.
If you're buying a CBM printer on Ebay, ask the seller to perform this simple test for you.
Office supply stores still sell tractor feed paper.