Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
If you can soak the part Citric Acid works well
Bilthamber Deox-C is a great product. Bilt Hamber Deox C Concentrated Rust Remover (1000g) https://amzn.eu/d/bndF2MG