Wow thank you for all the informative replies. I greatly appreciate all the information. I've learned more than I expected to.
Will a steel wool (000 grit) help slow the blade corrosion? I'm not opposed to a light clean but I wouldn't want to replace any parts on something this old.
The knife still kicks like a mule, which really impresses me because it has been played with by kids for the last 40 years at least lol.
The old guy was an interesting person and a few of his knives made their way to me. According to family legend, the switch was a bring back from his service in europe. He never discussed such things so it is hard to know.
If anyone is interested, here are the other blades of his that I ended up with: Couple of chunky knives my grandad left me
https://imgur.com/gallery/KmvqZb9