Squeaking "bushing" sound from rear

I have a nearly constant squeaky bushing-sounding squeak coming from the rear well of my '72 Dart Custom. If I push down on the rear fender even slightly with my hand when the car is stopped and not running I get a squeak. It's extremely annoying.

What in anyone's experience is the mostly likely cause of this?

If I just bring over new rear shocks for the mechanic to put in, will that most likely fix it?

Mechanics are fairly useless here in terms of telling you what to get to fix various problem. Diagnoses anywhere are challenging, and it's even more the case when they aren't experience with a particular year and model car.

I am not in a country where any parts are readily available so I have to come to the US and bring whatever I might need back in a suitcase. If I might need shocks, I'll just get them (doesn't hurt to replace them anyway). Whatever it might be I will be willing to just buy and take a chance that it's that. I can possibly record the sound with my phone and upload it if that would help.

Any help is appreciated!