I needed help with my Corona 3 and turned to the Yahoo Typewriter Group. After posting a few questions, I was immediately contacted by John Schellenger who sold me the correct ribbon spools for my machine. As I cleaned and cleaned this little typer I could tell I was making progress. The rust was gone and almost everything was moving freely. I had some more questions and heard back from Steve Dade in California who encouraged me to call him. Steve is a wealth of information on the Corona 3 and Corona 4. He let me know that my model is known as an "automatic" due to the ribbon reversal mechanism. Steve also let me know that the Corona 3 feeds ribbon from the front of the left spool and the back of the right spool - who knew! All in all, I learned a lot from this little machine. At 94 years of age, it still types great!
Another plus to my Corona 3 were the artifacts found in the case.
My Corona 3 must have stated its life in New York City and somehow traveled to New Hampshire.
One previous owner must have been worried about worn out ribbons!
Perhaps this is why my type slugs were pretty clean after 94 years!