By all means, get that darling to a vet. The lack of bladder control at his age is a sign of a problem. He has obviously been someones pet, taking to you and the house the way he has. A scared run-away? Dumped because he couldn't hold his juice?
Our husky is like that. She has never told us the story of her background. Had a choke chain which was way too tight, and no tags or chip. Was trained with hand commands, familiar with houses and sofas, but not house trained. Oh the frustrations, I could understand why someone might not want her, but the love she provides was worth all the trouble. By nature of the breed, she's a runner, but always came back when she managed to get out. If dogs get loose on a trip, there is no back. We feel fortunate that we could not find an owner, and we did look, for she is now the #1 girl in the house, and the husbands fave.
Get some OdorBan till you and the vet get that bladder thing cleared up. We'll be watching for update posts. Gut reaction - you didn't get a dog - the dog got you. Congrats!