No apologies necessary. We're all on here so we can ask questions and talk (sometimes about our dobes
So he's about 9 months old? It sounds like he's had a tough go of it--I'm glad you guys pulled him through.
It's a little hard to tell what his actual build is from your picture--he looks like he's not terribly muscular at this point, but I think as he matures and is able to exercise more, he'll bulk up a bit. His height and weight are just about within standards for an adult dobe even at this point, and male dobes tend to add muscle until they are 2 or even 3 even once they've reached their full height.
I'm not sure what you expect of him, but dobes are actually supposed to be a medium-sized dog...adult males 26-28 inches at the shoulder and usually about 75-95 pounds (34 to 43 kg) as a mature dog. There are people out there who brag about their giant over-weight dobe like that is how a good dobe is supposed to look, but dobes are really supposed be muscular but still trim and agile-looking.
Dobes can be prone to developing spine/neck troubles, so given that he's already had some inflammation as a result of parvo, you might even want to use an ordinary harness instead of a collar on him when you're out on walks, especially if he tends to be a puller. Don't use a Halti or head harness (one of those collar/harness contraptions designed to keep a dog from pulling); they can change a dog's gait a bit while you're walking them--they tend to walk a little sideways or with their head cocked around a little--and may be stressful on the dog's neck.