Well, Sammy's slooooowly coming around. Tiny, microscopic bits of progress, day by day, but it's in the right direction.
There's no doubt that Sammy is extraordinarily hormonal, and has been for 2-3 years. As near as we can determine (he's a rescue, so it's a matter of "educated guesses") he's about 13-14 years old.
Nonetheless, sitting beside his cage and talking softly to him, whether he's listening or not, seems to be continuing to have an effect. He's less "hyper-vigilant" and appears less stressed. While he still retreats to the far corner of his cage (while flaring, hissing, and pinning) on my approach, this generally occurs only first thing in the morning now, and after a few minutes of my speaking, he calms down.
Recently, I've started sitting beside his cage in the evening, when he's on top of it, with my arm resting on a small table beside the cage. In the past week or two, he's been climbing down the side of the cage & venturing out onto the table while my arm was there. In the past couple of days, he's started approaching my hand & plopping his beak down on the table, to get neck scritches. I do precisely as he asks, scritching gently, and stopping at the first sign of impatience on his part.
This seems to be working, as he's coming over for scritches increasingly often, and wanting it for longer periods of time. I take this as a BIG step forward. I'm doing everything in my power to regain his confidence & trust.
It's a loooong road, but...I want my Sammy back!!