Yeah, the clothes and the ad style looks like circa 1966 to me.
Yep, 1966. Dead on the money Inyo!
Good call — the ad is indeed from 1966. It appeared in Boy’s Life magazine.
http://www.snopes.com/vintage-daisy-gun-ad/
1966 would have been my guess too based on the styles and the poses. That was sort of the last year of the mid-century apogee as things were on the edge of breaking loose in 1967.