The 1979 and 1980 G's all came with 2-post steering wheels. Starting in 1981 I believe, the steering wheel became the same 4-point wheel used in the W123 at the time.
As such, the interlocking mechanism used by Mercedes-Benz was identical to the mechanisms used in the W124, W201 and other models.
What steering wheels have you guys upgraded to?
I currently have the W123-style 4-post, but am looking to upgrade to a pre-airbag W124 style, ideally finding a non-leather-wrapped wheel like this from a UK W124 (early 1990s):