It sounds like to me that you are as qualified as any of us to make a rifle from scratch that is at least as good as any kit. The pre-carved stocks still have plenty of wood to be removed and you still need to know what you are supposed to end up with. Others with more knowledge of Armstrong will have to chime in, but the ones I have seen didn't look like they were architecturally any different in the wrist, lock panels or forearm than say a Lancaster or York, at least what you can't see in a photo. The only thing that would be a question for me would be the profile of the upper forearm, if you really want to make sure it is right. To the best of my recollection, they were more rounded than V shaped and the lower forearms a bit higher than wide but not as extreme as a southern rifle of the same period. It is next to impossible to deduce the upper forearm shape form a photo. I have thought I had a good idea in the past only to find out when I had the gun in my hands that it was very different than what I thought from the photo. However, there are so many Armstrong's around, any number of owners should be able to confirm some important details. . I am pretty certain that if you live in the mid Atlantic, you can find an Armstrong or two to examine in person. The bottom line is, I think you should go the blank route and just do the additional research you need to feel comfortable. I am willing to bet that someone on this site can point you in the right direction.