dont know what sum of them things u mentioned are, only been on 2 planes in my life never again, always coach or cruise now, air crash investigators, are too advanced to have chains holding stuff together
'Airplane Anatomy 101' might be a good idea then - airplanes are full of chains, sprockets, gears, torque rods, bellcranks, bearings of all sorts, rod ends, cables of various sizes and types, sheet metal of various thicknesses, construction assembly and size, wiring, weldments, machinings, appliances like antennas and boxes, etc.
Much of that you can glean as you have here - from the historic pictures; but if you really want to play 'what's that rock' then you need to dig deep and consider that you may be looking at a very obscure construction detail or component you hadn't noticed or thought of before. That's where a thorough knowledge of what's in the guts of an airplane may help here. Jeff Hayden has offered up a few examples of crumpled metal stuff - that's the approach I'm speaking of - but much, much more.
A 'navigator's stool' was mentioned above - how about a toilet seat? Do you know what the 'honeybucket' looked like in NR16020? A seat belt buckle? An emergency gear handle? A seat frame bracket? A propeller counterweight or pitch change dome? How about a gascolator? Could you tell such a thing from it's marine counterpart, i.e. consider that if found you might be looking at something tossed from a boat?
It occurs to me that TIGHAR is well into all that - it's part of how you sort out possible targets from chaff, and even then you won't know until you can definitively identify a part.
As I noticed before, it is going to be a long, hard search.
LTM -