As I have mentioned earlier the earliest dated KS 98 bayonets I have seen is 1904 .I believe the First KS 98 bayonets came into DSWA in 1904 with the troop reinforcements which arrived on 11/06/1904 ,under lt. Gen von Trotha .These reinforcements were sent from Germany due to the outbreak of the Herero Rebellion in 1904.It is logical that they would bring the latest weaponary with them .
I found a photo taken in 1904 of uniforms worn during various periods in DSWA ,that might help.the soldier on the right, from the viewers perspective , is wearing the latest uniform with the M98 rifle,the new bandolier and I believe he seems to wear the KS 98 bayonet which was far shorter than the previous models often shown on Berlin studio photos.
This is not conclusive evidence though ,as the ofiicial bayonet as per “Bekleidungsvorschrift “ ( Uniform regulations) as specified by “ AKO “( Royal orders) dated 19/11/1896 for “Kaiserliche Schutztruppen “ ( Royal Protectorate Force) , was the Seitengewehr M71/84 .This bayonet only has a blade length of 250mm which is of coursevery similar in length to the KS 98 bayonet which has a blade length of 253mm.
I have recently come across KS98 with composite reddish grip ,marked ERFURT and dated 1913, which has the crosguard stamped KS 5259.
As you know I keep a list of all KS Bayonet details for many years and this is the latest marked KS 98 bayonet I have seen .The earliest I have seen is was dated 1904.