There's a patent number on the smaller of the blades near the hinge (2037943) that led me to a US patent from 1936 but it didn't tell me a lot about this particular knife. Any information on time period, brand, model, cleaning/restoring, etc is helpful. Thanks!

Additional notes:

• I cleaned off a decent amount of rust with some soap and WD-40 but the inner workings are still pretty messy
• The yellow layer on the handles is peeling off at the ends

Update: thank you all so much for the information! I've gotten a lot of information and leads on the knife. Still nothing definite on brand but you're probably right that it's a carbon steel blade with an ivory handle from about the 1950s. I'll be tending to it properly with your information on proper cleaning and sharpening of a knife like this. I'll post another update if I find anything more definite on brand/origin. Thanks again!