Ok here you go:
Here's a buyer's guide for you. It was written for the 560SEC by me and the site owner helped, about 10 years ago, but it addresses your car well if you think smaller motor and 2 more doors.
It is a fairly well regarded write up, and has a checklist too for buyers.
http://www.mbcoupes.com/buyersguide/buyersguide.htm
To get in depth for this specific exact model, come on over to the W126 section, and register there and ask. I am a Moderator of that forum and will give you a welcome if you want one.
http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/
You may find you wind up liking the car a lot more than you think. They are incredibly roomy, well built and reliable; There is one coupe with over 925,000 miles on it that was profiled in Autoweek, that has the same engine as yours.
It was last seen a few years ago at a car show in Cleveland. It had belonged to a shoe salesman in Nebraska or somewhere that could not take his sample shoes on the airplane so he bought it new.
Dark Green is an EXTREMELY rare color on these. Probably the interior is Palomino, or maybe black.
They are designed to be VERY easy for mechanics to work on, and independent shops love to work on them. You would be amazed at how quickly and easily you can do a brake job.
Also, parts are very easy to obtain for these, anything you need. Junkyards yield a mother lode of good parts for these cars, which were often sold to multimillionaires when new.
What is the VIN#? If you get it, then go and......
Run it on the free Russian Mercedes Benz VIN check site, and see what comes up in the way of equipment, options, and where it was delivered new
__________________

1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...
1995 E 420, 170k "The Red Plum" (sold)
2015 BMW 535i xdrive awd
Stage 1 DINAN, 6k, <----364 hp
1967 Mercury Cougar, 49k
2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive

(sold)