Found one that seems promising... https://jhpusa.com/products/momo-steering-wheel-hub-mercedes
There are many to be had for W123's up through 1983, but very hard to find for 1985 for some reason. What's the reason? Seems like 1970's-1983 had something different from 84/85 in this regard.

Either way.. Just so i understand.. is the point of these adapters to bring the car's steering column mount surface into a kind of universal standard that many aftermarket steering wheels will work with? Or am i to be looking for just one specific wheel type itself that this adapter is catering to?