Under no circumstances is what's been done to this car acceptable.
That said, the CLs have always been nice, but...if you're going to go for the W220 chassis, be prepared to make some expensive repairs due to age/mileage.
Someone mentioned the air struts - easy to replace, parts are 1200-1500 for GOOD ones.
Any of these with the early ABC can be trouble - the pumps tend to wear out and lose pressure when they sit. They are essentially impossible to rebuild yourself, and buying a GOOD one will be thousands.
Timing chains and chain guides are another thing to stay on top of with any M-B V8
The W220 is surprisingly easy to work on, but do NOT get a V12 in this car - the M275 is a very expensive motor to keep happy. If you want the real sleeper, and a much better car all around, get the previous generation CL 600 with the stunning M120 V12.