Front sight hoodFinally, what in God's good name is a sight hood, or a retaining screw? I've seen companies often saying they don't include them, but I have not the faintest idea what they are and why I would need them.
Installing/removing a front sight hood
While Russian Capture K98k's are missing the front sight hood, not all rifles had them originally. They were approved in December 1939 and started appearing in 1940.
The smaller triggerguard screws are locking screws AKA "capture screws". Not all triggerguards had locking screws. They were deleted later in the war.
RCs are also missing the cleaning rod, if one was originally fitted. Like the locking screws, it was deleted later in the war.
When looking at RC K98k's, look at the overall condition of the metal, and the condition and appropriateness of the stock. The current condition of the metal is probably more significant than which contractor originally made it. Earlier stocks had flat buttplates. Cupped buttplates started appearing in 1940.