>>Would anyone like to take a wild guess on his age from that pic?
>>I know thats like asking how old a mountain is, but still...

You state in your first posting that the tortoise is 3"-4". Assuming that's roughly accurate, then that is a sub-adult russian tortoise. Since it looks wild caught, it may well grow another inch or three before it is done.

I had one old-looking male that barely grew after several years and topped out at about 4.5". I had another female that was 4" at time of purchase and grew to about 7". Both were wild-caught animals. My other males grew to about 5.5", and females about 6.5" .

Age doesn't really matter much. It's definitely not a hatchling, so the type of care given is all the same. Varied diet, spacious housing, etc.