Series 1 Steering and horn question?

Howdy,

I was playing with cleaning up my steering wheel, and when I removed it, I noticed that there was no screws going from the horn insulator to the steering wheel. There was a spring under the insulator, and the horn works, so I am wondering if the two screws are needed? I assume it is correct that the spring goes under the insulator then the washer and then the nut? i

IF I need to replace those screws, what is the size? I looked at the reproduction part that motorsport has, it has the two screws, spring and insulator. If you screw  the insulator to the wheel,  does it still  have spring feel to it?

Any advice is greatly appreciated.

Thanks
Bob