A model 1896 carbine blade has to be taken out of the base to view the "C".

Note - An original sight pin is slightly tapered and should be driven from left to right, to remove.

Your pin appears a bit 'mushroomed' on both ends. It is likely a replacement/homemade pin.

Your blade may possibly just be a filed-down blade or homemade. You have to see the whole blade to tell.