I don't post much, I've been gone from this forum, for the most part for quite a while, but I wanted to tell you that I think you are doing right by Tucker. My dog prior to a B was my Eski, who had similar issues with trust. I was the only one he trusted completely, and he was very unpredictable (and dangerous) with strangers. I kept him safe and sound, and kept him from getting into trouble, by keeping him away from strangers, or muzzled. Even as my life circumstances changed, (family etc) I always figured out a way to help him get through it. He was a great dog, and accepted the fella and kids I acquired as his own family. We all loved him, and it worked for his whole life, until his kidneys finally quit due to age and I helped him across the bridge.
Only you know what is right for your family and your dog. Tucker will never forget what you have done for him, and you can know you did your best for him, even in difficult times.
Best of luck to you both….