That's a cute one! Here's my two cents: I think you should take him way out somewhere and let him go. I've rescued three big tortoises this year and took them to a protected wildlife area near my home.
Now! Having said that, my MIL has a Hermann's Tortoise in her garden which just appeared one day several years ago. We are quite attached to Agnes, and feed her salad and occasionally a small amount of fruit for a treat. She also eats grasses and other things growing in the garden. She is quite spoiled and will bite your toe if you don't bring her cucumbers.
The wildlife control officer we called said it's illegal here to deal in or possess the eggs, but not the tortoises themselves. She's energetic and successfully hibernates every winter. As a matter of fact, she's pretty groggy now and will probably not be awake for more than another couple of weeks. She always wakes up around the first week of April.