Tailgate Link Bracket Assembly Bushing Question

[Gregski]

I hope you can help me, I would like to powder coat these '71 fleetside tailgate straps, links, brackets, doodinguses but before I do so I would like to know if they have any plastic in them, if so I don't want to melt it in the oven, now mine have been media blasted and according to my eyecrometer I don't see any although there is some sort of a wobbly washer at the elbows, which I assume is metal

so I am wondering if these are supposed to be sorta wiggly and not super firm like door hinges, or are mine missing some bushings? perhaps they once had factory plastic bushings or bushes of any kind, or is it just metal on metal, bar or rivet caveman style

any help, advice, feed 'em back is greatly appreciated