[Dean Romig]

Brian, Charles A. King, Superintendant of the Parker Bros. Gun Works invented and patented on September 10, 1895 the Buttstock Reinforcing Rod.
I quote from page 127, Vol. 1 of Ther Parker Story King's own words:

"The use of woods of the so-called "curly" varieties is a well-known desideratum in the manufacture of stocks for shotguns and rifles, in order to get the peculiar ornamental effect thereof. In making a gunstock of wood of one of these curly varieties it is a matter of very frequent occurence that the grain of the wood at the neck or grip of the stock does not run lengthwise of that neck , but across it , which is something that renders the neck very liable indeed to breakage. So great is this liability of breakage in cases where the grain runs across rather than with the length of the neck or grip, manufactures of guns reject and refrain from using a large percentage of the very handsomest gunstocks they produce, and the loss resulting therefrom is a serious matter."

It would appear that not an awful lot of Parkers had this reinforcing rod installed. There is a 1907 DHE with the patent stamp in the stockwood immediately behind the grip cap indicating it had the rod installed and there are a number of Parkers with skeleton buttplates where the end of the rod appears in the correct position of an in-line boring for this rod but most of these lack the patent stamp.
It is unknown when this practice was discontinued but, in the case of this CH example, it had obviously been discontinued by then . . . how very unfortunately.