Happy to say I did! There were 2 prongs that locks the gear. One is coupled to the advance lever, and another one that I am not sure why exists. There was also a missing gasket based on the photos from the link you shared, which makes me believe the camera has had prior work before I received it.
Now on to the fix. As mentioned, the second prong was preventing the gear from moving. How I understood the mechanism is that when the silver lever is pressed, both prongs should release the gear. Since the second one was not coupled to the lever, it's effectively in a permanently locked state. To solve this, I could find a way to couple it or just remove the second prong and the tension spring holding it altogether. I went with the latter, and now it's working perfectly as intended.
Gonna post pictures later for documentation as I also unfortunately stripped the screw hole somehow and couldnt put in the final screw on that holds everything. I'll probably 3D print a pin to replace it.