The tab, and the ring it is attached to, should spring to the right/clockwise when facing the camera. Is the tab moveable, is it sticky, is there no spring tension?
As to the "release button out of place," could you elaborate?
Sorry, but I have no way to check the tab. It's not mine, but it is for sale. The release button is at the 12 o'clock position. It's usually at the 2 o'clock position in relation to the lens mount opening. My F4 has the same configuration. I just checked and the tab and button both rotate together. Perhaps this camera's mechanism is just gummed up and stuck in place. Is this common for the F3?
I checked my F3. Yeah, something is wrong/broken with this one. Not worth pursuing IMO, as the cost of getting it repaired (if possible) would make it cheaper to get one that works normally.
The ring the AI tab and release button are attached to is definitely in the wrong place. My guess is someone “repaired” this F3 and put it together wrong.
Wouldn’t touch it; who knows what else they “fixed?”
I had a FM which has stuck aperture tab. Upon careful inspection apparently the camera had been hit on the AI ring and it is dented. I removed the mount and wedged a screwdriver at the dent contact point and it worked. But if this F3 has detached AI spring then it needs more work by a professional. More parts need to be removed before you can reach the spring.