Whats funny about it in my eyes is the throttle plate is fully closed with the plate completely sealed against the wall of the throttle body. In other words the travel of the plate is not stopped by what looks like a throttle stop/idle screw. There is about 3mm space. I would have thought that the idle screw at least had the job of stopping the travel of the plate just a tiny bit before the the plate was fully closed, or at least to provide some respite to the throttle body wall from the plate due to the tension of the return spring.
Thinking about it a bit more, I guess the throttle plate is designed to be fully closed during idle. The idling is handled by the idle regulator through a totally different air/fuel circuit.
Will leave the throttle body as it is unless I hear otherwise, it was pretty gummed up so a good clean should have helped somewhat. Still thinking the screw/stop should be relieving the pressure of that spring... hmmmmmmm!