Info Request: Who was Colonel Larson?

I posted this scan from my collection of gun ads on my own blog a while back, and have received no comments, so maybe here it can get more viewers.

I think this ad is from the late 1960s, because Marlin uses the ZIP Code on their address. The ZIP Code system started in 1967, I think.

Who was this man who the ad refers to only as "Colonel Larson"? What was his story?

Any information would be appreciated.

Here's a little info

According to this page:
http://www.uwrf.edu/sports/sports0506/81induction.html

"Colonel Larson played football at the university for three years, in 1937-39. He helped the Falcons to the 1938 conference championship. He was named to the all-conference team as an end in 1939. He is the only UW-River Falls football player to play in the College All-Star game. He played end in the 1939 game. He also lettered in basketball in 1937-39, track in 1937-39, and swimming in 1938. After recovering from polio, he became the world's Rifle Champion in 1960. He was a holder of six world indoor records."

The university mentioned is the University of Wisconsin - River Falls.

He is My GrandFather

He lived in Whitehall, Wisconsin
His wife's Name is Lavearl Larson, and he has a Son and Daughter Named Gary and Judy Larson. Judy is my mother, who of course now is Judy Gilbertson. And Lavearl is living down with us now in Prairie du Chien, Wisconsin. Gary Larson lived in Eau Clarie, Wisconsin with his family who still resides there. Sadly my Uncle Gary has passed away recently. He was also a great man and will be missed. If you need more info you can email me at gilbertsonjc@gmail.com

Jeffrey C. Gilbertson