Congratulations! SnS is an excellent pin with great shots and rules.

You are probably fortunate that SnS is a Gottlieb System 3, one of the most reliable platforms out there. Biggest problem with any of the Gottlieb games of that era is a lack of game specific parts like ramps, plastics, and playfields. Whirlpool ramp is a weak spot as it is very thin and replacements are NLA. Under playfield hardware is heavy gauge and robust, won't be breaking any metal parts on that game. I have had one on location for nearly 2 years with only minor repairs needed. An expensive service overhaul is really not necessary.