Hey there fellow Minnesotan!
Please don't increase food intake beyond what is recommended by your brand. My dog was the same way when she was about that age and nearly everybody questioned whether I was feeding her or not...how insulting! But so many dogs in this country are overweight or obese, so it seems that people have started to think that's how they should look! If your guy has a healthy coat and plenty of puppy energy, then he is doing great! My female shepsky is now 2 and people still say she's so skinny...but her vets are always telling me she's perfect. She has one of the most beautiful, healthy coats I have ever seen and plenty of energy to spare (she is the fastest dog at the park!). Often times she's not even interested in her morning feeding or the treats I offer her. If your food is quality (like Taste of the Wild) then he does not need more than what you are feeding. The standard is that you should be able to feel the ribs, but not able to see individual rib bones (you will see is rib cage is out farther than his "waist"). Animals have no need to have excess fat over their rib cage - fat is to protect your organs (and store energy), but your ribs do that job for your lungs. Trust your vet - they want to see fit, healthy dogs. As he grows, he will fill out. I don't know about you, but I was an awfully scrawny kid when I hit my growing years, but ate my ma out of house and home!
That said, everyone loves pictures!
I attached one of Dellah from last winter, although she is still about the same size...and that is WITH her winter coat on! I couldn't find a good body shot with the face included...she never wants to cooperate with the camera!!!