The fuel injection system of a R107 SL is antiquated technology; nonetheless, it is not uncommon and is well comprehended. I really doubt that you would need to travel extensive distances, particularly to Germany, to locate someone capable of servicing it. Regarding your local garage, it is advisable to research this matter and other forums to get your own information and connections.
Based on my experience, it is entirely feasible to sustain these exceptional vehicles at a pretty little cost; nonetheless, it is crucial to acquire knowledge and establish the appropriate connections.