I have seen many rim blow steering wheels replaced on 1972 NYBs, and given the reliability of the mechanism did not improve in 1973, I suspect that the same is true for many 1973 NYBs that were originally equipped with a rimblow wheel.
I therefore wonder whether your wheels are original or not. More broadly, I wonder how many NYBs came out of the factory with the less fancy but reliable 3-spoke wheel, as opposed to a rim blow wheel. AFAIK, Jefferson fender tags do not show the steering wheel, so it'd be great if you guys could post your cars' build sheets.