When metal becomes hot, it undergoes color changes, which are the start colors, think of the bright red to orange in a blacksmith fire.
The clutch plate in the photo also has start colors. The link has been too hot. And that can / will have happened by driving a slipping clutch often and for a long time.
The link is therefore from a classic that…. Has been from a Real Old Lady. The clutch plate was worn down to the rivet lesson. And oh yes; the rest of the car was spotless.
But when purchasing your classic, always check the clutch for slipping. Because certainly with a front-wheel drive car, replacing the clutch is often quite an (expensive) job