i would consider the 201 as much of a Mercedes as the 202 or 203, but i see where you are coming from, the 201 was pretty brave for mercedes at the time. glad it worked out though as its led to an amazing bloodline. as far as "real mercedes" go. i once met a real snob who didnt consider the 260e he was trying to sell for his sister a real Mercedes either
guess its all a matter of perspective. as far as the choice goes i would buy the newer car if it looks good but convert the older car as its easier to work on and if god forbid something goes wrong down the road then you have the new car to fall back on. the 210 has a pretty good track record from what i understand but didnt have the solid feel of some early Mercedes. any problems from the first year would probably have been sorted throughout the years by the cars previous owners as there were several major recalls if im remembering correctly