I tried the first example with <script> at the very end. When you click on Link A or Link B, the corresponding div below it does receive focus. However, once that div is focused, you still can't navigate through the links that belong to Link A. If I am a keyboard user and I press Enter when Link A is focused, I should be able to tab through all the links that belong to Link A before going to Link B. That order is not currently followed.
The second example is also great. My only caveat with that one is that on a long page, it forces the browser down to where the target area is. I would prefer that the top links remain visible on the screen, at it appears in the first example.
Thank you both once again.