Thanks to sass and bucklife's input, I started thinking deeper about the 105's year of introduction, so I decided to ask Joe Houser before I moved forward with my t-shirt project. After all, the "Buck" stops with Joe.
Here is his reply...
Hello Tom,
While the 1961 version will be the most recognizable one, it isn’t when the 105 was introduced. If you want the date that represents its introduction, you should go with 1947. The "All purpose knife", which was later named the Pathfinder, can be seen in magazine ads from March of 1947. We don’t know when Hoyt made the first 105, but I feel confident in saying that 1947 was the first time we know of that it was advertised for sale in print. It's also the longest running model in the Buck line. I really like your idea of a shirt by the way!
Take care,
Joe Houser
Buck Knives Inc.
Introducing the unofficial, unauthorized, undeniably unique Pathfinder shirt...