C15A ignition switch. Instrument panel

[Jim Veliss]

Hi All ,
I am currently dismantling a chev dash panel , the ignition switch has a threaded ring on the front which I have loosened , but it wont unscrew completely because the lever part is in the way , anyone know how to remove it ?
Also there is a small hook on the left , what would this be for ?
There is an oil pressure guage added on the bottom left , I dont suppose it is a standard fitting , any ideas ?
Regards Jim.