I have a 7 months old boy in the same situation. His front legs are too short and he is about 2 inches taller in the rear than in the front. Anything else is in place. He was gorgeous at 8 weeks so I'm hoping that he'll come together in the next few months. It is hard to wait.
How is his topline??
The rear is 2 inches taller than the front. Top line starts deep at the withers and goes up to the rump. Not a nice view.
Length of body ....measured from withers to point of rump? Or from forechest area to point of rump. Supposedly from "point of shoulder" to point of rump....is that the top of shoulder (withers) or where shoulder blade meets upper arm?
"Proportion--Short-coupled; length from the point of the shoulder to the point of the rump is equal to or slightly longer than the distance from the withers to the ground. Distance from the elbow to the ground should be equal to one half of the height at the withers. The brisket should extend to the elbows, but not perceptibly deeper. The body must be of sufficient length to permit a straight, free and efficient stride; but the dog should never appear low and long or tall and leggy in outline. Substance--Substance and bone proportionate to the overall dog. Light, "weedy" individuals are definitely incorrect; equally objectionable are cloddy lumbering specimens. Labrador Retrievers shall be shown in working condition well-muscled and without excess fat."