The Lotus Grand Tourers

Where is the throttle return spring fitted on a 1989 Excel SE? I remember there was one hanging off the carbs when I dismantled them to take then off the euro carb, however as the engine was in bits when I got the car I have no idea where it attached to and I’ve forgotten how it was connected to the carbs! I suspect it may have been to the underside of the airbox? The service notes don’t show it

It's quite a long softish spring.
One end clips to a plate riveted to the underside of the air box (trumpet part). On my car the other end clips onto the ferril the accelerator cable end fits in but although it works, pretty sure that's not how they left the factory.
Tony

The one I got from SJS has an odd step near one end.. I'm hoping the reason for this will become apparent!

Think my connection point is a standard split pin through the air box and T bent over a washer