Rim Blow Steering wheel

[Challenger70]

I am missing some parts for the horn and the cap,does anyone have a diagram of what is required for my 70 challenger

 

[EW1BH27]

1970 Challenger Rim Blow cap pictures taken from eBay. "I am missing some parts for the horn" ???

 

[340challconvert]

Picture of back of wheel showing wire connect to rim blow horn insert