Edit 2: The fulcrum assembly was a bushing-rivet pin-bushing setup; I broke out the unbroken bushing and drilled the outer plate holes from 9mm to 1/2" (the outer diameter of the inner part of the bushing was approximately 13mm; 1/2" was the closest I could get without ordering specialized parts.

For about $6USD I got four washers to replace the bushings' outer step and a 1/2"x4" bolt and nut; I replaced the fulcrum pin assembly completely with the bolt setup and kind of jammed the lever spring around the bolt.

Works a charm and is way stronger than it ever could have been originally :D

Thanks, all!

Edit: A bushing in the fulcrum axle was shattered. No way to fix meaningfully without a replacement mechanism.

Got a 5-year-old office chair someone in my complex was about to throw away.

It leans back evenly when the height lever is pulled out, but it's wobbly only to the back right when in its non-rocking mode.

Here's a video of the movement. Is it cooked?

Looked up the SKU: https://www.officedepot.com/a/products/8638586/Realspace-Treswell-Bonded-Leather-High-Back/

I actually had one of these a long time ago but it was falling apart at its seams. Much older and poorly taken care of, also a chair i'd found.

This one's in much better condition aside from the wobble; the bolts are all solid, the underpart of the seat itself perfectly intact.