Eames ESU 200-C 1st and 2nd generation compatibility of parts question  

Besides the most obvious difference (the legs/base), the parts/components are basically interchangeable but the ESU's were produced in a very short time and are considered rare, the last thing you want to do is to alter the configuration as it was ordered by the original owners back in the early 1950s.

The Eames designed Herman Miller showroom in Los Angeles from 1950 with an ESUesque facade like the Eames Case Study House might be worthy of restoration though. (The street view is from Google and the period black and white image is by Julius Schulman)