Welcome to the forum, and to the wonderful world of Krags!  I must warn you... Krags are very addicting!

You appear to have a very nice Krag there.  I can't add anything more than Whig or Butlersrangers have already told you.  As for the sling, there are several that would be correct.  The later Trapdoor sling would have been originally used.  However, the 1907 sling is also correct, as they were used after the sling's adoption.  If you intend on shooting it in Vintage Rifle Matches, such as the Roosevelt Commemorative Match at Camp Perry, then the 1907 is the best choice for position shooting.  However, I would recommend that you get a new sling from Turner Saddlery, or one of the other manufacturers.  Using an original can result in damage to the sling from the stress (I know... I did this and ruined one).  Also, although not period correct, the M1 web sling used on the Garand is also acceptable for match shooting (my son prefers this sling, while I use a Turner 50" 1907 reproduction).

Enjoy the Krag and happy shooting!