I think the "safety" issue comes up, not because of the age of the equipment, but the maintenance of it, and how it is used.
For example, if this service is well-maintained, and continues to support a 1930 lifestyle, no problem. If, however, various occupants have added will-nilly to the system, in order to support the air conditioner, microwave, stereo, bathroom, etc...then there are sure to be major safety issues- of which the service equipment is but a small part.