mountney wheel and boss here, works fine (pity about the rest of the car though), just 1 wire and the horn push earths it through the steering column.
Ihave a horn push from a Ferrari 308, which has a MOMO wheel and that works in a simlar way.
On my old de-ville i just cut the spokes off the original wheel, kept the default horn push and used that as a mount for a another mountney with no boss.