Here is the illustrated parts list for your engine:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6ntzHVJ1DajI.pdf

Here is the operator's manual:
http://bsintek.basco.com/BriggsDocumentDisplay/mssAIQ-K_ny7tH217FzoPu.pdf

Here is the illustration from the operator's manual showing the carburetor linkage:
[Linked Image]

As you can see, the free end of the anti-oscillation spring should attach to the hole right beside the attachment of the throttle link. Since it does not seem to be the right length for this, there is probably something wrong with the way the opposite end of the spring is anchored to the throttle butterfly itself. Perhaps you could post a picture of that end so we can try to work out what is wrong.

The silver choke wire appears to be the original wire link that should be coupled to the speed control system at what is now the free end of the wire. There are parts missing, however. Here is the illustration from the workshop manual:
[Linked Image]

Here is the governor linkage from your engine, rotated to the same view as the illustration:
[Linked Image]

Note that your speed control cable comes in from the bottom of the picture. This is the version shown faintly on the illustration, not the one shown as full lines.

As you can see, there are several parts missing from your engine (see red oval), and a wiring change has been made (the black wire with the red connector has been installed). At this point it would be very helpful if someone else with a 281707 or another engine with the rack and pinion governor control and coupled choke, could post pictures and explanations. Is the missing apparatus in the red oval a coupled kill switch? (The terminal at the bottom of the picture seems to be a kill wire terminal, with a wire running up to a contact that probably meets a pin on the pinion when the speed control is set to minimum. At present a wire has been run from the bottom terminal directly to the dashboard starter switch, so the mechanically coupled switch is not required.) If so, the main question is where and how the control wire for the coupled choke attaches to the back of the rack and pinion mechanism. Most likely it attaches to the rotating pinion which meshes with the vertical rack, behind the mounting plate.