Houston,
I agree with you about "Why did the NSKK use the SA runic inset and not their own emblem?" There has to be an answer to this, and I do have some provisional information about it, but I prefer to wait until I have it more thoroughly confirmed.
Regarding the NSKK Eagle as a grip inset, yes, I have seen a couple of these, and I whereas I once gave them the benefit of the doubt, I am no longer convinced that they were authentic. They did not fit well in the grip and that I find questionable. Of course other people will say that poor workmanship and sloppy fitting is normal for the subject. Sorry, I am one of those guys who believes otherwise.
On the issue of the known photographs showing the "NSKK Honour Dagger" with the wide cartouche, I have yet to see any evidence that suggests either of the existing daggers is positively one of those shown in the photographs. What happens when we find another dagger with the same unique (well, semi-unique) features? Maybe there will be some future clues that allow us to advance a little bit further.
Jason, you have made some comment about the relative values of the Huhnlein Honour Dagger and the regular SA Honour Dagger, and I am pleased to benefit from your considerable experience.
Am I correct in believing that you state that an NSKK High Leader Honour Dagger, with chains (and maybe, perhaps, a wide cartouche at the conflusion of the chains), complete with damascus blade, raised and gilded inscription, but a recessed intalglio etch of the "Huhnlein signature" - and that such a piece is worth no more than a regular SA Honour Dagger without chains? Is this what you are stating? Please confirm.
FJS
