You have found a very rare and attractive Dog...

No matter what kind of dog it is, I would try and find the owner unless it appears to have been badly abused (lot of scars, very thin, afraid of certain ppl, etc.)

I don't care if it's a dirty little mutt, you have a right to try to find the owner. Is that fair to the dog to keep it because you want it? Especially if you are keeping a rare and attractive dog - sounds like you are interested in trying to sell it for money. No, when I find a stray, I try to find it's owner (does it have tags and a collar? could be easy to find the owner) I check with vets and shelters to see if anyone is looking for the pet. Only after I exhausted my search would I consider attempting to keep the dog if I could, or finding it a new home. Granted, if the dog seemed abused or neglected, I would reconsider trying to find the owner.

being an honest person and knowing how dogs can be treated in kennels/etc, i would try my hardest to find the owner but keep the dog and care for it the best i could until the owner shows up.