The trouble is that the FL052/1 bushing has an OD of 20.08mm and the ID of the Throttle Arm is 17.5mm. Lots of interference, plainly.
I can't get a good image on the BB that matches what I'm seeing on my car. It looks like the bushing has been welded to the Throttle Arm. My question: Is this normal, or has my throttle arm been "upgraded"?
Thoughts on what I've got and what to do are much appreciated!
Your arm looks fine, I think from the picture the issue is that the outer metal ring of the old bushing is still in the hole in the arm. If that's the case, youu need to get that out with a press, or cut it with a hacksaw or something to remove it.