I recently bought a lot of Lego that was mostly 1990's bricks, and I had a few things I couldn't identify. One I found on Bricklink, but the other two are baffling me. Here is the first one, a different sort of hinged plate that I hadn't seen before:
You would think these would be "modified plates," but I couldn't find them.
Even stranger are these pieces (two varieties): These obviously allow for perpendicular placement of other pieces, and again I would think they were modified plates, but they aren't, at least in Bricklink.
I'm most curious to see how these pieces were used in sets. Thank you!