Bought our '72 350SL 18 yrs ago as a mid life crisis (50) toy.
At that time it had done 124k miles. Now has 145k on clock. Not exactly a daily driver!
Have had a few problems - mainly cracked exhaust manifolds. Other than that, just upgrades like new leather, mats and a recent DIY tune up that first went wrong but finally worked out (see other thread!).
Used as sunny day car and back up when one of the other two Benzes are in for service. (an '85 diesel and a '98 E-class)