Well ...
Now I have to admit ...
that I should have read in more detail what already is on Wiki.
Well,
to make a long story short:
There are two types of steering wheels for the 230 and early 250 SL that I am aware of:
Type I and Type II as described. And Type III for the late 250 & 280 SL of course.
However, for the hub pad discussion this is
a little more complex.
There are - to me - at least four different sub-types of pads for the 230/250 and two for the late 250/280 around.
Type I as described on Wiki with grey plastic base and full chrome 160 millimeter outer chrome ring.
Type II as described on Wiki with grey plastic base and half chrome - half black outer chrome ring.
Both have the center star together with a separate surrounding chrome ring (the 64 mm ring to say so).
Type II "b" with black (slightly flatter) plastic base and half chrome - half black outer chrome ring.
Center star has also its surrounding chrome ring (64 millimeters) but the pad material is a little stiffer than before.
Type II "c" with black plastic base, completely different pad (stiffer, more coarse) with half chrome - half black outer 160 mm chrome ring.
Center star has a larger diameter (the Mercedes star itself, not the emblem) and no surrounding chrome ring anymore. Center star is glued to the pad by a foamy double-faced adhesive tape.
This is the modern replacement (A1114600642 and 0742) which is still available today.
Type III "a"
Late 250/280 and "/8"-horn pad with center star with surrounding chrome ring (cannot be disassembled) - NLA
Type III "b"
Currently available "/8" horn pad without surrounding chrome ring around the center star emblem. (Ivory colored) Pad is more coarse and more greyish than Type III "a". Still available today with a 115 parts number.
My August 1964 230 had the type II steering wheel with Type I hub pad which is supposed to be original. So, the design of steering wheel and hub pad did not change exactly at the same time.
Well, that's all what I am aware about horn/center pads so far ...
I have to get pictures of all my horn/center pads and sort that correctly together with Alfred and put it on Wiki. I shouldn't do that alone; Alfred is already more knowledgable here than me.
Sorry for the confusion....
Achim
(unaware horn pad collector)