Currently looking into sourcing and restoring/fitting a 4 spoke RS wheel, one of the few mods i'll make on a standard S2, but I want to be sure on what is needed for it, i have sourced an actual wheel but it comes bare with no accessories

I have seen there is a specific boss for the mk4 escort, is this the only one that can be used due to horn contact ring etc as im sure mk3 escort had horn on a stalk?
The horn push, will any 3 or 4 spoke RS wheel work?
And lastly, if anybody has any of these bits lying around, let me know if your interested in selling the correct boss, horn push etc