What Breed Is My Dog?

My boyfriend and I came home one day and this cutie was on our porch. We called in with our city to report the finding, took him to the vet, no tattoo or micro chip, so we kept him, and named him Jaxon! He's probably about a year and a half now, and we're not too sure what breed his is. We've been told by vets that he looks to be a type of Malinois (blue/fawn) or German Shepherd mix.

He's very sweet, and loving. He likes to bark when people/other dogs walk by the house. He's incredibly friendly and amazing with kids; there is a 5 year old and a 2 year old around him daily. He is a quick learner, and quite smart. He gets excited easily, but is easy to settle down. He also gets along well and plays well with other dogs. If he's annoyed or wants to be left alone he'll let out a little bit of a growl, but hasn't shown any aggression aside from that really.

He's probably just under 2 feet at the shoulder and weighs about 55lbs. He's fairly leanly built, he's muscular, but could probably be a bit more bulky. He's got a tail like a Malinois, but it's curls right around.

Here's a picture of him beside my Papillon mix, he's a little bit taller as he's slightly crouching down to tug with her, but she can walk clear under him.

It was hard to pick just 1 picture, I'm such a crazy dog mom and take a bunch.