Grab the idler arm itself & give it a shake. Failure of the original bushes after thirty something years is rare, but not unknown, which is why several companies make urethane replacement bushes for them.

If your shock absorbers have been replaced with cartridge inserts, then make sure that the gland nut at the top of the strut tube is tight. It should be accessable by just jacking up that side of the car. Most times you can even leave the wheel on.

If this nut is loose, the shock insert can rattle up & down in the tube making terrible noises. Tightening it is a very low cost fix.