I had a 560sl
Did alot of work on it from fixing the vacuum pods to painting it
Not that it was beat up but I kept upgrading and tweaking
It was a good car but after upgrading to my 500sl
There was very little in modern features on the 560
When a car gets 20 years old its going to need work/ tuning
From frame and engine mounts , shocks fluids, interior leather,engine seals ,timming chain, valve seals, injection hoses, exhaust, brakes, rubber seals ,rubber molding.
But thats on all cars they get tired after that long
you may not need all of this but believe me it will need care
but if you like to work on cars its not a bad car to work on

The 500sl I have is a 2000 which makes it easier because technology
does away with some problems and engineers keep improving things
I know the soft top hase lots of cylinders but I love the convience of it
Car is more responsive and corning is tight, seating is set up better
sound is is way better, lines are cleaner ( if thats what yuo want)
Bottom line is I was never sorry I upgraded car is a sweet ride
I can say it is the best car I owned.
money and your prefrence is the real factor on which one is the one for you
My friend has a 2007 sl 500
thats another level all its own
Good luck on your decision and whatever it is , it will be what you want
and you will be happy , they are great cars