I have had straight pins rust, or rather oxidize, so I just bought new ones.
If your rotary blades have rusted you might try cleaning them with Naval Jelly (Home Depot) rust remover. They are just too expensive to replace. Good luck.
The irony of it is that you live in Denver which is always sooo dry, you never need to worry about those things. I lived in Highlands Ranch for 8 years, and miss it.