These things REEK airplane - and makeshift to meet some impromptu need, as well - such as could EASILY be the case for a one-off use mission, like produced by hand in a shop somewhere along the way to secure some oddball something while flying around the world in an overloaded Lockheed...
But why would she/he remove them from the airplane and take them all the way to the Seven Site? What possible utility could they have to a castaway?
I see them as being a home-grown modification to the sextant box (which we KNOW was at the Seven Site). Recall that Harold Gatty, a world class navigator, said of the sextant box, "... that it was used latterly merely as a receptacle." Why would he say that? What was there about the box that told Gatty that it had been used not to carry a sextant but merely as a box to carry things in?
Brandis sextant boxes are outfitted with all kinds of wooden compartments and dividers. If you wanted to use the box "merely as a receptacle" they would get in the way. Did Gatty see a box that had been gutted of its interior features?
Certainly possible, Ric, as are lots of things. I'm not throwing darts at the sextant box idea - I remember that and of course it is possible.
But so might someone remove a floor board and transport it for some reason - something to sit or sleep on, or for rudimentary shade - or any number of other reasons, and organic stuff like wood doesn't last long on Niku, does it? So we could be seeing the remnants after the wood 'went away' -
Which doesn't fully account easily for the presence of wood fibers still evident in one piece, but not the other - unless they were removed from the wood deliberately by different means (unscrewing in one case, prying in the other). Or perhaps that was happenstance - one screw could have had a somewhat loose fit originally and never 'took up' much bite from the wood, whereas the one with fibers remaining may have been more tightly bound into the parent structure.
All ideas at this point in my view. And I've heard from one fellow off-forum who says he seen this kind of stuff all over the place... but what continues to stick out to me is 'yeah, but aircraft aluminum?' OK, could have been made from aircraft scraps (I'd say 'it is') and we have a number of examples of that from Niku, not necessarily from the Electra - but despite that wise fellow's general observation, these are still peculiarly 'purpose built' for something that may have well been a bit more athletic or dynamic than ordinary household use -
And a sextant box might fit that, as might securing something to the floor of the Electra - or any number of similar things.
My point was simply to stir interest in looking at possibilities: there could yet be a photo clue out there somewhere.
And the sextant box idea makes sense - it would be far more easily transported and would have far more obvious utility value, in my opinion, than a floor board.