Hi Dave.
Here is my take on it for what its worth. It sounds just like the original to my ears, would I sell everyting to buy one? No. Not because there is anything wrong with the guitar, but because my playing is not of a standard to justify such an expensive instrument. But in your capable hands, it sounds as it should. yes there is the odd note and echo differences, but that is not the guitar. you have even added the odd extra note here and there, is that bad? no.
Hank has said, while they (the shads) appreciate the effort of people to replicate their sound. He believes that should be the starting point, not the end product. That people should bring their own individuality and thus develope their own style, I think you have done this. and Hank would approve.
That said, I would love to sound like Hank. But listen to different recordings of the same tune, any shads tune, but especially Sleepwalk. every recording is different, even today he makes subtle changes to That Sound.
Its a beautiful instrument, beautifully played by someone who will get both the enjoyment and use from it to justify the expense.
Would I like one? Damn right I would. Carry on pickin. Ian