Tom / Rob,
It's really a worse try than you think: The knife photographed in Bradford's "Wilderness Cookery" is a mid 50's Model 3-6. The knife I posted a photo of is a C 1950 Model 7-5. If you look closely, that's a small stamp on the Model 7. The only era that a Model 3-6 or 3-7 carried that small stamp was in the 40's.
As a side note: The pin in the 7-5 is nickel silver. That only happened on a small percentage of knives around 1950. A number of years ago I had a bet with Doug (Silverknife): He claimed they were aluminum. I think he still owes me a beer
Best,