Hello Alex,
Here are pictures of the press button releases on two 98/05 bayonets. The first one is an unaltered Imperial era sawtooth. The second and third pics are of a Weimar reworked Police issue sawtooth removed bayonet. It was my understanding that many of the Weimar reworked pieces had the press button replaced with a slotted one. Hope this answers your question.

100_3392 (Medium).jpg (49.48 KB, 223 downloads)
100_3393 (Medium).jpg (46.45 KB, 221 downloads)
100_3375 (Medium).jpg (56.52 KB, 223 downloads)
WANTED TO REPURCHASE!! Walther pistol Model PP - ac code - Ser. No. 382000P - REWARD FOR INFO ABOUT THIS PISTOL!!