I would assume that the >>KS<< denotes Krupp'schen Spezial - Gewehrlaufstahl(mit 3 Ringen). So
K - Krupp
S - Stahl? or Spezial?????

Anyway, light choke had an additional fee of 5 Marks and heavy choke warranted a price hike of 10 Marks. Sauer evidently worked w/ the Berlin - Halensee Institute(darstellt)?-(there was a shooting Competition nearby also) to devise shot patterns in the 75cm ring. This effort is noted by either the Large or Small Crowns, with one being shooting performance & the other quality. The Shooting Performance Crown resulted in a surcharge(Mehrpreis) of at least 25 Marks, and more, depending on just how much ammo was used.

Cheers,

Raimey
rse