Thank you for the input on the 12/j.r. and I misspoke, 3/k.d. =3. Kavallerie-Division.The usual place for unit markings on a Kar 98 ist the top of the butt plate. 12./J.R ... means 12th company, infantry regiment ???? In those times, and even to this day, "I" is often written as "J" as soon as it stands alone. So definitely "Infanterie-Regiment".
"Kriegs Division" would mean "war division"; what's that supposed to mean???
This style of marking (company numer / regiment) was introduced only after the war.