This is a well bred GSD. His eyes are 'dark as possible'. This is the GSD breed standard. Look at the eyes of sheriff dept and police dogs on their facebook pages. Eyes not yellow, not light but super dark. His legs are heavy and straight, not toeing out, he has a masculine head. By his rich red and black color he looks to be of west German lines.
The GSDs of west Germany all have to be titled in something in order to register their puppies. This breeds for dogs intelligent and highly trainable The titles are Herding, Tracking and Schutzhund. Schutzhund has three levels- Obedience (they are sent over an obstacle course while the master stands at the side of the course) Tracking- they follow a scent trail and find 'clues' such as hats or gloves which they lie down and hold between their paws until the handler comes. Level three is police work where they find a 'perp' hiding, hold them barking there until the handler comes. Then the perp is escorted away. The perp then attacks the handler (while wearing a bite suit) and the dog runs him down, bites and holds him without being told. Schutzhund contests draw big crowds of spectators in Germany
As to his disposition, a dog of this quality would be expected to have strong nerve. His timidity shows that he may have come from one of those nuts who raise dogs on chains, that beat and abuse them. This is not the Lassie show, he is not yearning for someone. Dogs live in the moment. All his moments now are good moments and his trust in humans is rebuilding.
If this were my dog I would have posters on every telephone pole and feed store in this county and the adjoining ones.