It's strange a green cheek would have these issues, they're typically pretty laid back birds. But no 2 birds are ever the same and these issues do need to be addressed. THANK YOU for coming here for help instead of just getting rid of him

20 years is a log time to have a pet, and with some work I'm sure your family and your bird will be thankful everyone worked together to resolve these issues.
It sounds to me as if some bad behaviors stemming from the move were unintentionally reinforced and over the long term became bad habits. If it were me, I would go back to the beginning with him and re-train him using the kind of techniques you would if you had just adopted him. Yes, he may already know this stuff, but structured training re-introduces positive interactions and positive behaviors in an out of control bird. Whenever my bird acts up, he gets to do some 'basic training' exercises right away. Not that he forgot how to, but it just reminds him that he knows how to behave. He would *much rather* be hanging out and having fun and doing new things than doing boring step up drills or other training exercises (or if he's really misbehaving, having a time out to calm himself). Parrots, amazons especially, are a whole lot smarter than we often give them credit for AND they want to be having fun with their flock or playing with toys, not screaming, biting and acting up. Actually, they are a whole lot like toddlers in this regard. They need for the 'authority figure' (you) to make behaving more rewarding than acting up. They also need structure, routine and consistent responses to positive and negative behaviors.
If possible, move your birds cage to a new position in the room because he's obviously quite comfortable misbehaving where he is now. Give him a new view as you begin a new routine with him. Make sure he's on a good routine of sleep/wake and times he is interacting/self entertaining during the day. Your husband should start with daily trust building exercises. He can sit by the cage and talk or read out loud softly to him and reward him with treats and verbal praise when he approaches in a non-aggressive manner. Since he is more tolerating of you, you could start introducing target training and have daily sessions where you reinforce positive interactions in a structured setting with training exercises. Be sure to incorporate things like stepping up (yes he knows how, but may need to be 'refreshed' that he should do so when he's asked

), bite pressure, recall and even some simple tricks. You want to reinforce positive interactions you are in control of. As he reestablishes trust with your husband, he can also start becoming involved in training sessions too to further build a positive bond with the bird. It will take time, weeks, months, a year... who knows? Go at his pace but keep in mind every small step in the right direction is better than whats going on currently.
Screaming is much harder to "train out of" a bird, but with time and consistency can be done. First, you do need to run through a checklist to identify if he's screaming because he has a care need that needs to be addressed at that moment (low on food, wants a new toy, sees something frightening ext...) or if he's just being 'difficult'. A bird who is screaming for attention should be ignored. When he makes 'nice' noises, he should be praised and rewarded with attention/treats. Simply ignoring the bad noises doesn't work if you aren't also establishing a way he can vocalize appropriately (i.e. conversation level noises/words/whistles ect...). And while I know some amazons like to be real perch potatoes, if you aren't already, make sure your rotating toys and including foraging activities regularly to keep him occupied with self-rewarding activities during times you can't be with him. Best of luck and stick around. LOTS of knowledge on this forum, and lots of people who WANT to help you have a good relationship with your bird
