Not sure about an older Series 2 with a spoked steering wheel, but mine (2a) has a female splined insert inside the base of the steering wheel, which easily slides onto (and off) the male splined top of the steering column. That allows the steering wheel orientation to be adjusted or "aligned" with the direction of the front wheels. And there's only one large bolt (inside the wheel, behind the horn button) holding my wheel onto the shaft. Maybe your steering wheel and steering column are frozen, or rusted together? And just maybe, just maybe, the PO used some sort of binding agent (not necessary, of course) to "glue" the wheel to the steering column? Believe me: when you're not the first owner of a Series Rover, expect the unexpected!
David
Daily Driver:
1971 Series 2a, 88, Soft-top, LHD