Actually .... the Riflemann sling was designed by Richard Mann, author of "the scout rifle study". It is an excellent choice in my opinion. very nice blending of the need for a sling to carry well AND function as a shooting sling.
right now I use either the Riflemann sling or one of Andy's leather slings. Slings like the military 1907, while excellent shooting slings and function as an ok carry sling, often do not match up to a bolt action sporting rifle very well. experiences may vary.
Anyway, the Riflemann sling would complement the Art of the rifle quite nicely...and speaking of the art of the rifle. I agree, excellent book. however, check the gunsite proshop for a copy, don't pay the ridiculous prices off the used market on Amazon. though the kindle price is reasonable. Gunsite has been getting in copies from somewhere and not charging super inflated pricing. Looks like they still have some.
If you poke around Richard's Youtube channel you can find a couple videos explaining the sling.