Some of the members here get hung up on factory correctness. That is one type of 113 enthusiast (I'm one).
But, the 113 also lends itself (like the 190 SL) to some exquisite, personalized restorations. I've noticed the European restorers work with far more latitude in their finishes, mostly to add bling to the engine bay. The 113 is a great looking, very drivable and reliable (when properly restored and sorted) vintage car to be enjoyed by purists and those that just love the car for whatever reason. It will never be a classic, losing points in a collection for not being 100% factory correct.
While some members refer to Concours restoration, but not factory correct, correct me if I'm wrong, but I'm not aware of any 113 specific Concours judging. I know there's MBCA judging, but I'm not sure those guys know all the ins and outs of the 113. I don't think THIS club has a Concours judging where the knowledge of members here would really certify correctness of a restoration.
All that said, the car looks beautiful and if it rings your bell, it'd be hard to go wrong. Biggest issue, is it just a pretty car? Too many are gorgeous but don't run or drive worth a ****.