Removable Steering Wheel - Esprit S2

[The Sentinel]

Does anyone know if you can get a removable wheel boss for a S2 Esprit?
Or is there one available that fits between the original boss & wheel?
It has the original 3 spoke MOMO wheel on at the moment.
Also can anyone recommend a replacement 'flat bottomed' wheel I could replace it with that would be a straight swap (6 bolts).

Thanks