Seely was a legendary gunsmith, an innovator and a major force in the development of Bench Rest shooting. There are plenty folks on this board who knew him and will speak for his work, I'm not one of the fortunate ones.
Here is a thread from someone else in your position who asked the same question.
Further info on the Masker family.
Seeley's son, Jerry, is still competing and is the only person, so far, to make the Benchrest Hall of Fame by points earned only in the Unlimited/Heavy Bench class.