There appears to be a filament caught under the screw of the smaller one. In "screw-heads" image attached to this post
How soon after discovery was that picture taken?
Not sure about significance of filiment (whether original to the find or something picked-up along the way), but as to the 'eye' effect on the smaller, open holes (both parts exhibit this) - this is an effect of hand-drilling with a power tool. I commented on this feature some time ago regarding these parts.
When hand-drilling with a high-speed bit it is common to get 'chatter' - a rapid oscillation of the drill bit tip as it begins to purchase into the material. As the hole deepens the bit tip tends to stabilize and the end result is the mostly round hole we see that goes all the way through.
Having done a good bit of hand-drilling on small pieces that are also hand-held with grips (or a vice if one has it handy enough, but not always near when needed) these parts appear to me to have been drilled with a power tool (how much of that was happening on Gardner?). Further, this appears to have been done 'on the fly', i.e. someone needed an improvised 'gidgy' for some reason and roughed these out very nicely but in quick fashion on a limited workbench, if not plane-side. The teeth could easily be produced with a common bastard file of some fairness - the apex of the notches is not acute beyond 90 degrees.
These don't seem like they were produced on Gardner for at least some of these reasons. There are examples of things that were apparently done on Gardner, like a metal comb, etc. Maybe some of the tooling marks among these things can be compared to determine more about possible cottage-origins for the 'gidgies' on Niku, or not, but my strong suspicion is they were not made there.
So, IMO - not only are these made of aviation-grade material (wood screws excepted), they bear the marks of aviation hand-work including hand-drilling with a high-speed bit in a power drill.