I've written previously about Triple Nickel Books, a line of paperbacks put out in the 1950's by Ben Solomon and Woody Gelman. These 15 cent softcover stories seem to follow two lines of characters: historical ones like Davy Crockett and Wild Bill Hickok, and 'tween adventurers/sleuths such as Barbie Lane or the Power Boys.
The Power Boys seem to be the most popular part of the series, which ran to about fifteen books overall, near as I can tell, and the Power Boys were the subject of at least eight of them. Here's a representative cover:
The author is Arthur Benwood, which is an amalgam of Ben and Woody's first names. It's not clear if they wrote the Power Boys stories or were just being clever with the pseudonym. Like any serious line of books aimed at the youth of the country, an advertising and marketing campaign had to be developed. One approach taken by the Triple Nickelers was to use the back of 1950's Exhibit cards. Check out this Walt Dropo, provided by Friend o' the Archive Glen over at Net54:
Isn't that something?! You can see the Mystery of Marlow Mansion title in the ad to boot. Compare to the back cover of a standard Triple Nickel (yet again referring to the title above):
It's worth noting that while a later series of hardcover books also known as The Power Boys, published in the mid 1960's, was unrelated to the previous incarnation, the father of the latter brood was called Thomas, so maybe the author (Mel Lyle) too inspiration from the past in a way.
A Stan Musial Exhibit with Triple Nickel advertising also is known; the ad back is rare even among the universe of scarcity that defines Exhibit backs of the era.